diff --git a/locale/circuitpython.pot b/locale/circuitpython.pot
index 9148569ecd..17bcb663b5 100644
--- a/locale/circuitpython.pot
+++ b/locale/circuitpython.pot
@@ -874,6 +874,11 @@ msgstr ""
 msgid "EXTINT channel already in use"
 msgstr ""
 
+#: shared-module/synthio/MidiTrack.c
+#, c-format
+msgid "Error in MIDI stream at position %d"
+msgstr ""
+
 #: extmod/modure.c
 msgid "Error in regex"
 msgstr ""
@@ -1197,6 +1202,10 @@ msgstr ""
 msgid "Invalid DAC pin supplied"
 msgstr ""
 
+#: shared-bindings/synthio/__init__.c
+msgid "Invalid MIDI file"
+msgstr ""
+
 #: ports/atmel-samd/common-hal/pwmio/PWMOut.c
 #: ports/cxd56/common-hal/pwmio/PWMOut.c ports/nrf/common-hal/pwmio/PWMOut.c
 #: ports/raspberrypi/common-hal/pwmio/PWMOut.c shared-bindings/pwmio/PWMOut.c
@@ -1877,7 +1886,7 @@ msgstr ""
 msgid "Read-only filesystem"
 msgstr ""
 
-#: shared-module/bitmaptools/__init__.c shared-module/displayio/Bitmap.c
+#: shared-module/displayio/Bitmap.c
 msgid "Read-only object"
 msgstr ""
 
@@ -2488,10 +2497,6 @@ msgstr ""
 msgid "buffer is smaller than requested size"
 msgstr ""
 
-#: shared-bindings/audiocore/RawSample.c
-msgid "buffer must be a bytes-like object"
-msgstr ""
-
 #: extmod/ulab/code/ulab_create.c
 msgid "buffer size must be a multiple of element size"
 msgstr ""
@@ -2933,7 +2938,7 @@ msgid "f-string: single '}' is not allowed"
 msgstr ""
 
 #: shared-bindings/audiocore/WaveFile.c shared-bindings/audiomp3/MP3Decoder.c
-#: shared-bindings/displayio/OnDiskBitmap.c
+#: shared-bindings/displayio/OnDiskBitmap.c shared-bindings/synthio/__init__.c
 msgid "file must be a file opened in byte mode"
 msgstr ""
 
diff --git a/ports/atmel-samd/mpconfigport.mk b/ports/atmel-samd/mpconfigport.mk
index 7be9e203a8..4dab750fbb 100644
--- a/ports/atmel-samd/mpconfigport.mk
+++ b/ports/atmel-samd/mpconfigport.mk
@@ -39,6 +39,7 @@ CIRCUITPY_BUILTINS_POW3 ?= 0
 CIRCUITPY_COMPUTED_GOTO_SAVE_SPACE ?= 1
 CIRCUITPY_FREQUENCYIO ?= 0
 CIRCUITPY_JSON ?= 0
+CIRCUITPY_SYNTHIO ?= 0
 CIRCUITPY_TOUCHIO_USE_NATIVE ?= 1
 
 # No room for HCI _bleio on SAMD21.
diff --git a/py/circuitpy_defns.mk b/py/circuitpy_defns.mk
index bb177c5d07..44a52dd355 100644
--- a/py/circuitpy_defns.mk
+++ b/py/circuitpy_defns.mk
@@ -280,6 +280,9 @@ endif
 ifeq ($(CIRCUITPY_SUPERVISOR),1)
 SRC_PATTERNS += supervisor/%
 endif
+ifeq ($(CIRCUITPY_SYNTHIO),1)
+SRC_PATTERNS += synthio/%
+endif
 ifeq ($(CIRCUITPY_TERMINALIO),1)
 SRC_PATTERNS += terminalio/% fontio/%
 endif
@@ -523,6 +526,8 @@ SRC_SHARED_MODULE_ALL = \
 	socket/__init__.c \
 	storage/__init__.c \
 	struct/__init__.c \
+	synthio/MidiTrack.c \
+	synthio/__init__.c \
 	terminalio/Terminal.c \
 	terminalio/__init__.c \
 	time/__init__.c \
diff --git a/py/circuitpy_mpconfig.h b/py/circuitpy_mpconfig.h
index eedda7ad73..801e1867e7 100644
--- a/py/circuitpy_mpconfig.h
+++ b/py/circuitpy_mpconfig.h
@@ -728,6 +728,13 @@ extern const struct _mp_obj_module_t supervisor_module;
 #define SUPERVISOR_MODULE
 #endif
 
+#if CIRCUITPY_SYNTHIO
+#define SYNTHIO_MODULE         { MP_OBJ_NEW_QSTR(MP_QSTR_synthio), (mp_obj_t)&synthio_module },
+extern const struct _mp_obj_module_t synthio_module;
+#else
+#define SYNTHIO_MODULE
+#endif
+
 #if CIRCUITPY_TIME
 extern const struct _mp_obj_module_t time_module;
 #define TIME_MODULE            { MP_OBJ_NEW_QSTR(MP_QSTR_time), (mp_obj_t)&time_module },
@@ -897,6 +904,7 @@ extern const struct _mp_obj_module_t msgpack_module;
     STORAGE_MODULE \
     STRUCT_MODULE \
     SUPERVISOR_MODULE \
+    SYNTHIO_MODULE \
     TOUCHIO_MODULE \
     UHEAP_MODULE \
     USB_CDC_MODULE \
diff --git a/py/circuitpy_mpconfig.mk b/py/circuitpy_mpconfig.mk
index fea1f937ec..d55e7c90ab 100644
--- a/py/circuitpy_mpconfig.mk
+++ b/py/circuitpy_mpconfig.mk
@@ -305,6 +305,9 @@ CFLAGS += -DCIRCUITPY_STRUCT=$(CIRCUITPY_STRUCT)
 CIRCUITPY_SUPERVISOR ?= 1
 CFLAGS += -DCIRCUITPY_SUPERVISOR=$(CIRCUITPY_SUPERVISOR)
 
+CIRCUITPY_SYNTHIO ?= $(CIRCUITPY_AUDIOCORE)
+CFLAGS += -DCIRCUITPY_SYNTHIO=$(CIRCUITPY_SYNTHIO)
+
 CIRCUITPY_TERMINALIO ?= $(CIRCUITPY_DISPLAYIO)
 CFLAGS += -DCIRCUITPY_TERMINALIO=$(CIRCUITPY_TERMINALIO)
 
diff --git a/shared-bindings/_typing/__init__.pyi b/shared-bindings/_typing/__init__.pyi
index cc4a0a4391..174c002fdc 100644
--- a/shared-bindings/_typing/__init__.pyi
+++ b/shared-bindings/_typing/__init__.pyi
@@ -38,7 +38,7 @@ WriteableBuffer = Union[
 """
 
 AudioSample = Union[
-    audiocore.WaveFile, audiocore.RawSample, audiomixer.Mixer, audiomp3.MP3Decoder
+    audiocore.WaveFile, audiocore.RawSample, audiomixer.Mixer, audiomp3.MP3Decoder, synthio.MidiTrack
 ]
 """Classes that implement the audiosample protocol
 
@@ -46,6 +46,7 @@ AudioSample = Union[
   - `audiocore.RawSample`
   - `audiomixer.Mixer`
   - `audiomp3.MP3Decoder`
+  - `synthio.MidiTrack`
 
   You can play these back with `audioio.AudioOut`, `audiobusio.I2SOut` or `audiopwmio.PWMAudioOut`.
 """
diff --git a/shared-bindings/audiocore/RawSample.c b/shared-bindings/audiocore/RawSample.c
index 23a2d3f0be..13339222c1 100644
--- a/shared-bindings/audiocore/RawSample.c
+++ b/shared-bindings/audiocore/RawSample.c
@@ -30,7 +30,6 @@
 #include "py/binary.h"
 #include "py/objproperty.h"
 #include "py/runtime.h"
-#include "shared-bindings/microcontroller/Pin.h"
 #include "shared-bindings/util.h"
 #include "shared-bindings/audiocore/RawSample.h"
 #include "supervisor/shared/translate.h"
@@ -83,26 +82,23 @@ STATIC mp_obj_t audioio_rawsample_make_new(const mp_obj_type_t *type, size_t n_a
     audioio_rawsample_obj_t *self = m_new_obj(audioio_rawsample_obj_t);
     self->base.type = &audioio_rawsample_type;
     mp_buffer_info_t bufinfo;
-    if (mp_get_buffer(args[ARG_buffer].u_obj, &bufinfo, MP_BUFFER_READ)) {
-        uint8_t bytes_per_sample = 1;
-        bool signed_samples = bufinfo.typecode == 'b' || bufinfo.typecode == 'h';
-        if (bufinfo.typecode == 'h' || bufinfo.typecode == 'H') {
-            bytes_per_sample = 2;
-        } else if (bufinfo.typecode != 'b' && bufinfo.typecode != 'B' && bufinfo.typecode != BYTEARRAY_TYPECODE) {
-            mp_raise_ValueError(translate("sample_source buffer must be a bytearray or array of type 'h', 'H', 'b' or 'B'"));
-        }
-        common_hal_audioio_rawsample_construct(self, ((uint8_t *)bufinfo.buf), bufinfo.len,
-            bytes_per_sample, signed_samples, args[ARG_channel_count].u_int,
-            args[ARG_sample_rate].u_int);
-    } else {
-        mp_raise_TypeError(translate("buffer must be a bytes-like object"));
+    mp_get_buffer_raise(args[ARG_buffer].u_obj, &bufinfo, MP_BUFFER_READ);
+    uint8_t bytes_per_sample = 1;
+    bool signed_samples = bufinfo.typecode == 'b' || bufinfo.typecode == 'h';
+    if (bufinfo.typecode == 'h' || bufinfo.typecode == 'H') {
+        bytes_per_sample = 2;
+    } else if (bufinfo.typecode != 'b' && bufinfo.typecode != 'B' && bufinfo.typecode != BYTEARRAY_TYPECODE) {
+        mp_raise_ValueError(translate("sample_source buffer must be a bytearray or array of type 'h', 'H', 'b' or 'B'"));
     }
+    common_hal_audioio_rawsample_construct(self, ((uint8_t *)bufinfo.buf), bufinfo.len,
+        bytes_per_sample, signed_samples, args[ARG_channel_count].u_int,
+        args[ARG_sample_rate].u_int);
 
     return MP_OBJ_FROM_PTR(self);
 }
 
 //|     def deinit(self) -> None:
-//|         """Deinitialises the AudioOut and releases any hardware resources for reuse."""
+//|         """Deinitialises the RawSample and releases any hardware resources for reuse."""
 //|         ...
 //|
 STATIC mp_obj_t audioio_rawsample_deinit(mp_obj_t self_in) {
diff --git a/shared-bindings/audiocore/RawSample.h b/shared-bindings/audiocore/RawSample.h
index b07add2dd1..71056f30c3 100644
--- a/shared-bindings/audiocore/RawSample.h
+++ b/shared-bindings/audiocore/RawSample.h
@@ -27,7 +27,6 @@
 #ifndef MICROPY_INCLUDED_SHARED_BINDINGS_AUDIOIO_RAWSAMPLE_H
 #define MICROPY_INCLUDED_SHARED_BINDINGS_AUDIOIO_RAWSAMPLE_H
 
-#include "common-hal/microcontroller/Pin.h"
 #include "shared-module/audiocore/RawSample.h"
 
 extern const mp_obj_type_t audioio_rawsample_type;
diff --git a/shared-bindings/audiocore/WaveFile.c b/shared-bindings/audiocore/WaveFile.c
index 73943f980f..5cf6deb2ed 100644
--- a/shared-bindings/audiocore/WaveFile.c
+++ b/shared-bindings/audiocore/WaveFile.c
@@ -44,7 +44,7 @@
 //|         """Load a .wav file for playback with `audioio.AudioOut` or `audiobusio.I2SOut`.
 //|
 //|         :param typing.BinaryIO file: Already opened wave file
-//|         :param ~_typing.WriteableBuffer buffer: Optional pre-allocated buffer, that will be split in half and used for double-buffering of the data. If not provided, two 512 byte buffers are allocated internally.
+//|         :param ~_typing.WriteableBuffer buffer: Optional pre-allocated buffer, that will be split in half and used for double-buffering of the data. If not provided, two 256 byte buffers are allocated internally.
 //|
 //|
 //|         Playing a wave file from flash::
diff --git a/shared-bindings/synthio/MidiTrack.c b/shared-bindings/synthio/MidiTrack.c
new file mode 100644
index 0000000000..65fc7a4ee1
--- /dev/null
+++ b/shared-bindings/synthio/MidiTrack.c
@@ -0,0 +1,169 @@
+/*
+ * This file is part of the Micro Python project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2021 Artyom Skrobov
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include <stdint.h>
+
+#include "lib/utils/context_manager_helpers.h"
+#include "py/binary.h"
+#include "py/objproperty.h"
+#include "py/runtime.h"
+#include "shared-bindings/util.h"
+#include "shared-bindings/synthio/MidiTrack.h"
+#include "supervisor/shared/translate.h"
+
+//| class MidiTrack:
+//|     """Simple square-wave MIDI synth"""
+//|
+//|     def __init__(self, buffer: ReadableBuffer, tempo: int, *, sample_rate: int = 11025) -> None:
+//|         """Create a MidiTrack from the given stream of MIDI events. Only "Note On" and "Note Off" events
+//|         are supported; channel numbers and key velocities are ignored. Up to two notes may be on at the
+//|         same time.
+//|
+//|         :param ~_typing.ReadableBuffer buffer: Stream of MIDI events, as stored in a MIDI file track chunk
+//|         :param int tempo: Tempo of the streamed events, in MIDI ticks per second
+//|         :param int sample_rate: The desired playback sample rate; higher sample rate requires more memory
+//|
+//|         Simple melody::
+//|
+//|           import audioio
+//|           import board
+//|           import synthio
+//|
+//|           dac = audioio.AudioOut(board.SPEAKER)
+//|           melody = synthio.MidiTrack(b"\\0\\x90H\\0*\\x80H\\0\\6\\x90J\\0*\\x80J\\0\\6\\x90L\\0*\\x80L\\0\\6\\x90J\\0" +
+//|                                      b"*\\x80J\\0\\6\\x90H\\0*\\x80H\\0\\6\\x90J\\0*\\x80J\\0\\6\\x90L\\0T\\x80L\\0" +
+//|                                      b"\\x0c\\x90H\\0T\\x80H\\0\\x0c\\x90H\\0T\\x80H\\0", tempo=640)
+//|           dac.play(melody)
+//|           print("playing")
+//|           while dac.playing:
+//|             pass
+//|           print("stopped")"""
+//|         ...
+//|
+STATIC mp_obj_t synthio_miditrack_make_new(const mp_obj_type_t *type, size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
+    enum { ARG_buffer, ARG_tempo, ARG_sample_rate };
+    static const mp_arg_t allowed_args[] = {
+        { MP_QSTR_buffer, MP_ARG_OBJ | MP_ARG_REQUIRED },
+        { MP_QSTR_tempo, MP_ARG_INT | MP_ARG_REQUIRED },
+        { MP_QSTR_sample_rate, MP_ARG_INT | MP_ARG_KW_ONLY, {.u_int = 11025} },
+    };
+    mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
+    mp_arg_parse_all(n_args, pos_args, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
+
+    mp_buffer_info_t bufinfo;
+    mp_get_buffer_raise(args[ARG_buffer].u_obj, &bufinfo, MP_BUFFER_READ);
+
+    synthio_miditrack_obj_t *self = m_new_obj(synthio_miditrack_obj_t);
+    self->base.type = &synthio_miditrack_type;
+
+    common_hal_synthio_miditrack_construct(self,
+        (uint8_t *)bufinfo.buf, bufinfo.len,
+        args[ARG_tempo].u_int,
+        args[ARG_sample_rate].u_int);
+
+    return MP_OBJ_FROM_PTR(self);
+}
+
+//|     def deinit(self) -> None:
+//|         """Deinitialises the MidiTrack and releases any hardware resources for reuse."""
+//|         ...
+//|
+STATIC mp_obj_t synthio_miditrack_deinit(mp_obj_t self_in) {
+    synthio_miditrack_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    common_hal_synthio_miditrack_deinit(self);
+    return mp_const_none;
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_1(synthio_miditrack_deinit_obj, synthio_miditrack_deinit);
+
+STATIC void check_for_deinit(synthio_miditrack_obj_t *self) {
+    if (common_hal_synthio_miditrack_deinited(self)) {
+        raise_deinited_error();
+    }
+}
+
+//|     def __enter__(self) -> MidiTrack:
+//|         """No-op used by Context Managers."""
+//|         ...
+//|
+//  Provided by context manager helper.
+
+//|     def __exit__(self) -> None:
+//|         """Automatically deinitializes the hardware when exiting a context. See
+//|         :ref:`lifetime-and-contextmanagers` for more info."""
+//|         ...
+//|
+STATIC mp_obj_t synthio_miditrack_obj___exit__(size_t n_args, const mp_obj_t *args) {
+    (void)n_args;
+    common_hal_synthio_miditrack_deinit(args[0]);
+    return mp_const_none;
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(synthio_miditrack___exit___obj, 4, 4, synthio_miditrack_obj___exit__);
+
+//|     sample_rate: Optional[int]
+//|     """32 bit value that tells how quickly samples are played in Hertz (cycles per second)."""
+//|
+STATIC mp_obj_t synthio_miditrack_obj_get_sample_rate(mp_obj_t self_in) {
+    synthio_miditrack_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    check_for_deinit(self);
+    return MP_OBJ_NEW_SMALL_INT(common_hal_synthio_miditrack_get_sample_rate(self));
+}
+MP_DEFINE_CONST_FUN_OBJ_1(synthio_miditrack_get_sample_rate_obj, synthio_miditrack_obj_get_sample_rate);
+
+const mp_obj_property_t synthio_miditrack_sample_rate_obj = {
+    .base.type = &mp_type_property,
+    .proxy = {(mp_obj_t)&synthio_miditrack_get_sample_rate_obj,
+              (mp_obj_t)&mp_const_none_obj,
+              (mp_obj_t)&mp_const_none_obj},
+};
+
+STATIC const mp_rom_map_elem_t synthio_miditrack_locals_dict_table[] = {
+    // Methods
+    { MP_ROM_QSTR(MP_QSTR_deinit), MP_ROM_PTR(&synthio_miditrack_deinit_obj) },
+    { MP_ROM_QSTR(MP_QSTR___enter__), MP_ROM_PTR(&default___enter___obj) },
+    { MP_ROM_QSTR(MP_QSTR___exit__), MP_ROM_PTR(&synthio_miditrack___exit___obj) },
+
+    // Properties
+    { MP_ROM_QSTR(MP_QSTR_sample_rate), MP_ROM_PTR(&synthio_miditrack_sample_rate_obj) },
+};
+STATIC MP_DEFINE_CONST_DICT(synthio_miditrack_locals_dict, synthio_miditrack_locals_dict_table);
+
+STATIC const audiosample_p_t synthio_miditrack_proto = {
+    MP_PROTO_IMPLEMENT(MP_QSTR_protocol_audiosample)
+    .sample_rate = (audiosample_sample_rate_fun)common_hal_synthio_miditrack_get_sample_rate,
+    .bits_per_sample = (audiosample_bits_per_sample_fun)common_hal_synthio_miditrack_get_bits_per_sample,
+    .channel_count = (audiosample_channel_count_fun)common_hal_synthio_miditrack_get_channel_count,
+    .reset_buffer = (audiosample_reset_buffer_fun)synthio_miditrack_reset_buffer,
+    .get_buffer = (audiosample_get_buffer_fun)synthio_miditrack_get_buffer,
+    .get_buffer_structure = (audiosample_get_buffer_structure_fun)synthio_miditrack_get_buffer_structure,
+};
+
+const mp_obj_type_t synthio_miditrack_type = {
+    { &mp_type_type },
+    .name = MP_QSTR_MidiTrack,
+    .make_new = synthio_miditrack_make_new,
+    .locals_dict = (mp_obj_dict_t *)&synthio_miditrack_locals_dict,
+    .protocol = &synthio_miditrack_proto,
+};
diff --git a/shared-bindings/synthio/MidiTrack.h b/shared-bindings/synthio/MidiTrack.h
new file mode 100644
index 0000000000..d44d4c3bb7
--- /dev/null
+++ b/shared-bindings/synthio/MidiTrack.h
@@ -0,0 +1,43 @@
+/*
+ * This file is part of the Micro Python project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2021 Artyom Skrobov
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef MICROPY_INCLUDED_SHARED_BINDINGS_SYNTHIO_MIDITRACK_H
+#define MICROPY_INCLUDED_SHARED_BINDINGS_SYNTHIO_MIDITRACK_H
+
+#include "shared-module/synthio/MidiTrack.h"
+
+extern const mp_obj_type_t synthio_miditrack_type;
+
+void common_hal_synthio_miditrack_construct(synthio_miditrack_obj_t *self,
+    const uint8_t *buffer, uint32_t len, uint32_t tempo, uint32_t sample_rate);
+
+void common_hal_synthio_miditrack_deinit(synthio_miditrack_obj_t *self);
+bool common_hal_synthio_miditrack_deinited(synthio_miditrack_obj_t *self);
+uint32_t common_hal_synthio_miditrack_get_sample_rate(synthio_miditrack_obj_t *self);
+uint8_t common_hal_synthio_miditrack_get_bits_per_sample(synthio_miditrack_obj_t *self);
+uint8_t common_hal_synthio_miditrack_get_channel_count(synthio_miditrack_obj_t *self);
+
+#endif // MICROPY_INCLUDED_SHARED_BINDINGS_SYNTHIO_MIDITRACK_H
diff --git a/shared-bindings/synthio/__init__.c b/shared-bindings/synthio/__init__.c
new file mode 100644
index 0000000000..d5165001fc
--- /dev/null
+++ b/shared-bindings/synthio/__init__.c
@@ -0,0 +1,136 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2021 Artyom Skrobov
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include <string.h>
+
+#include "py/mperrno.h"
+#include "py/obj.h"
+#include "py/runtime.h"
+#include "extmod/vfs_fat.h"
+
+#include "shared-bindings/synthio/__init__.h"
+#include "shared-bindings/synthio/MidiTrack.h"
+
+//| """Support for MIDI synthesis"""
+//|
+//| def from_file(file: typing.BinaryIO, *, sample_rate: int = 11025) -> MidiTrack:
+//|     """Create an AudioSample from an already opened MIDI file.
+//|     Currently, only single-track MIDI (type 0) is supported.
+//|
+//|     :param typing.BinaryIO file: Already opened MIDI file
+//|     :param int sample_rate: The desired playback sample rate; higher sample rate requires more memory
+//|
+//|
+//|     Playing a MIDI file from flash::
+//|
+//|           import audioio
+//|           import board
+//|           import synthio
+//|
+//|           data = open("single-track.midi", "rb")
+//|           midi = synthio.from_file(data)
+//|           a = audioio.AudioOut(board.A0)
+//|
+//|           print("playing")
+//|           a.play(midi)
+//|           while a.playing:
+//|             pass
+//|           print("stopped")"""
+//|     ...
+//|
+STATIC mp_obj_t synthio_from_file(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
+    enum { ARG_file, ARG_sample_rate };
+    static const mp_arg_t allowed_args[] = {
+        { MP_QSTR_file, MP_ARG_OBJ | MP_ARG_REQUIRED },
+        { MP_QSTR_sample_rate, MP_ARG_INT | MP_ARG_KW_ONLY, {.u_int = 11025} },
+    };
+    mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
+    mp_arg_parse_all(n_args, pos_args, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
+    if (!MP_OBJ_IS_TYPE(args[ARG_file].u_obj, &mp_type_fileio)) {
+        mp_raise_TypeError(translate("file must be a file opened in byte mode"));
+    }
+    pyb_file_obj_t *file = MP_OBJ_TO_PTR(args[ARG_file].u_obj);
+
+    uint8_t chunk_header[14];
+    f_rewind(&file->fp);
+    UINT bytes_read;
+    if (f_read(&file->fp, chunk_header, sizeof(chunk_header), &bytes_read) != FR_OK) {
+        mp_raise_OSError(MP_EIO);
+    }
+    if (bytes_read != sizeof(chunk_header) ||
+        memcmp(chunk_header, "MThd\0\0\0\6\0\0\0\1", 12)) {
+        mp_raise_ValueError(translate("Invalid MIDI file"));
+        // TODO: for a multi-track MIDI (type 1), return an AudioMixer
+    }
+
+    uint16_t tempo;
+    if (chunk_header[12] & 0x80) {
+        tempo = -(int8_t)chunk_header[12] * chunk_header[13];
+    } else {
+        tempo = 2 * ((chunk_header[12] << 8) | chunk_header[13]);
+    }
+
+    if (f_read(&file->fp, chunk_header, 8, &bytes_read) != FR_OK) {
+        mp_raise_OSError(MP_EIO);
+    }
+    if (bytes_read != 8 || memcmp(chunk_header, "MTrk", 4)) {
+        mp_raise_ValueError(translate("Invalid MIDI file"));
+    }
+    uint32_t track_size = (chunk_header[4] << 24) |
+        (chunk_header[5] << 16) | (chunk_header[6] << 8) | chunk_header[7];
+    uint8_t *buffer = m_malloc(track_size, false);
+    if (f_read(&file->fp, buffer, track_size, &bytes_read) != FR_OK) {
+        mp_raise_OSError(MP_EIO);
+    }
+    if (bytes_read != track_size) {
+        mp_raise_ValueError(translate("Invalid MIDI file"));
+    }
+
+    synthio_miditrack_obj_t *result = m_new_obj(synthio_miditrack_obj_t);
+    result->base.type = &synthio_miditrack_type;
+
+    common_hal_synthio_miditrack_construct(result, buffer, track_size,
+        tempo, args[ARG_sample_rate].u_int);
+
+    m_free(buffer);
+
+    return MP_OBJ_FROM_PTR(result);
+}
+MP_DEFINE_CONST_FUN_OBJ_KW(synthio_from_file_obj, 1, synthio_from_file);
+
+
+STATIC const mp_rom_map_elem_t synthio_module_globals_table[] = {
+    { MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_synthio) },
+    { MP_ROM_QSTR(MP_QSTR_MidiTrack), MP_ROM_PTR(&synthio_miditrack_type) },
+    { MP_ROM_QSTR(MP_QSTR_from_file), MP_ROM_PTR(&synthio_from_file_obj) },
+};
+
+STATIC MP_DEFINE_CONST_DICT(synthio_module_globals, synthio_module_globals_table);
+
+const mp_obj_module_t synthio_module = {
+    .base = { &mp_type_module },
+    .globals = (mp_obj_dict_t *)&synthio_module_globals,
+};
diff --git a/shared-bindings/synthio/__init__.h b/shared-bindings/synthio/__init__.h
new file mode 100644
index 0000000000..14af1a5805
--- /dev/null
+++ b/shared-bindings/synthio/__init__.h
@@ -0,0 +1,34 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2021 Artyom Skrobov
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef MICROPY_INCLUDED_SHARED_BINDINGS_SYNTHIO___INIT___H
+#define MICROPY_INCLUDED_SHARED_BINDINGS_SYNTHIO___INIT___H
+
+#include "py/obj.h"
+
+// Nothing now.
+
+#endif  // MICROPY_INCLUDED_SHARED_BINDINGS_SYNTHIO___INIT___H
diff --git a/shared-module/synthio/MidiTrack.c b/shared-module/synthio/MidiTrack.c
new file mode 100644
index 0000000000..0827945ab5
--- /dev/null
+++ b/shared-module/synthio/MidiTrack.c
@@ -0,0 +1,212 @@
+/*
+ * This file is part of the Micro Python project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2021 Artyom Skrobov
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "py/runtime.h"
+#include "shared-bindings/synthio/MidiTrack.h"
+
+#define LOUDNESS 0x4000  // 0.5
+#define BITS_PER_SAMPLE 16
+#define BYTES_PER_SAMPLE (BITS_PER_SAMPLE / 8)
+#define SILENCE 0x80
+
+STATIC uint8_t parse_note(const uint8_t *buffer, uint32_t len, uint32_t *pos) {
+    if (*pos + 1 >= len) {
+        mp_raise_ValueError_varg(translate("Error in MIDI stream at position %d"), *pos);
+    }
+    uint8_t note = buffer[(*pos)++];
+    if (note > 127 || buffer[(*pos)++] > 127) {
+        mp_raise_ValueError_varg(translate("Error in MIDI stream at position %d"), *pos);
+    }
+    return note;
+}
+
+STATIC void terminate_span(synthio_miditrack_obj_t *self, uint16_t *dur, uint16_t *max_dur) {
+    if (*dur) {
+        self->track[self->total_spans - 1].dur = *dur;
+        if (*dur > *max_dur) {
+            *max_dur = *dur;
+        }
+        *dur = 0;
+    } else {
+        self->total_spans--;
+    }
+}
+
+STATIC void add_span(synthio_miditrack_obj_t *self, uint8_t note1, uint8_t note2) {
+    synthio_midi_span_t span = { 0, {note1, note2} };
+    self->track = m_realloc(self->track,
+        (self->total_spans + 1) * sizeof(synthio_midi_span_t));
+    self->track[self->total_spans++] = span;
+}
+
+void common_hal_synthio_miditrack_construct(synthio_miditrack_obj_t *self,
+    const uint8_t *buffer, uint32_t len, uint32_t tempo, uint32_t sample_rate) {
+
+    synthio_midi_span_t initial = { 0, {SILENCE, SILENCE} };
+    self->sample_rate = sample_rate;
+    self->track = m_malloc(sizeof(synthio_midi_span_t), false);
+    self->next_span = 0;
+    self->total_spans = 1;
+    *self->track = initial;
+
+    uint16_t dur = 0, max_dur = 0;
+    uint32_t pos = 0;
+    while (pos < len) {
+        uint8_t c;
+        uint32_t delta = 0;
+        do {
+            c = buffer[pos++];
+            delta <<= 7;
+            delta |= c & 0x7f;
+        } while ((c & 0x80) && (pos < len));
+
+        if (c & 0x80) {
+            mp_raise_ValueError_varg(translate("Error in MIDI stream at position %d"), pos);
+        }
+
+        dur += delta * sample_rate / tempo;
+
+        switch (buffer[pos++] >> 4) {
+            case 8: { // Note Off
+                uint8_t note = parse_note(buffer, len, &pos);
+
+                // Ignore if not a note which is playing
+                synthio_midi_span_t last_span = self->track[self->total_spans - 1];
+                if (last_span.note[0] == note || last_span.note[1] == note) {
+                    terminate_span(self, &dur, &max_dur);
+                    if (last_span.note[0] == note) {
+                        add_span(self, last_span.note[1], SILENCE);
+                    } else {
+                        add_span(self, last_span.note[0], SILENCE);
+                    }
+                }
+                break;
+            }
+            case 9: { // Note On
+                uint8_t note = parse_note(buffer, len, &pos);
+
+                // Ignore if two notes are already playing
+                synthio_midi_span_t last_span = self->track[self->total_spans - 1];
+                if (last_span.note[1] == SILENCE) {
+                    terminate_span(self, &dur, &max_dur);
+                    if (last_span.note[0] == SILENCE) {
+                        add_span(self, note, SILENCE);
+                    } else {
+                        add_span(self, last_span.note[0], note);
+                    }
+                }
+                break;
+            }
+            case 10:
+            case 11:
+            case 14: // two data bytes to ignore
+                parse_note(buffer, len, &pos);
+                break;
+            case 12:
+            case 13: // one data byte to ignore
+                if (pos >= len || buffer[pos++] > 127) {
+                    mp_raise_ValueError_varg(translate("Error in MIDI stream at position %d"), pos);
+                }
+                break;
+            case 15: // the full syntax is too complicated, just assume it's "End of Track" event
+                pos = len;
+                break;
+            default: // invalid event
+                mp_raise_ValueError_varg(translate("Error in MIDI stream at position %d"), pos);
+        }
+    }
+    terminate_span(self, &dur, &max_dur);
+
+    self->buffer_length = max_dur * BYTES_PER_SAMPLE;
+    self->buffer = m_malloc(self->buffer_length, false);
+}
+
+void common_hal_synthio_miditrack_deinit(synthio_miditrack_obj_t *self) {
+    m_free(self->buffer);
+    self->buffer = NULL;
+    m_free(self->track);
+    self->track = NULL;
+}
+bool common_hal_synthio_miditrack_deinited(synthio_miditrack_obj_t *self) {
+    return self->buffer == NULL;
+}
+
+uint32_t common_hal_synthio_miditrack_get_sample_rate(synthio_miditrack_obj_t *self) {
+    return self->sample_rate;
+}
+uint8_t common_hal_synthio_miditrack_get_bits_per_sample(synthio_miditrack_obj_t *self) {
+    return BITS_PER_SAMPLE;
+}
+uint8_t common_hal_synthio_miditrack_get_channel_count(synthio_miditrack_obj_t *self) {
+    return 1;
+}
+
+void synthio_miditrack_reset_buffer(synthio_miditrack_obj_t *self,
+    bool single_channel, uint8_t channel) {
+
+    self->next_span = 0;
+}
+
+STATIC const uint16_t notes[] = {8372, 8870, 9397, 9956, 10548, 11175, 11840,
+                                 12544, 13290, 14080, 14917, 15804}; // 9th octave
+
+audioio_get_buffer_result_t synthio_miditrack_get_buffer(synthio_miditrack_obj_t *self,
+    bool single_channel, uint8_t channel, uint8_t **buffer, uint32_t *buffer_length) {
+
+    if (self->next_span >= self->total_spans) {
+        *buffer_length = 0;
+        return GET_BUFFER_DONE;
+    }
+
+    synthio_midi_span_t span = self->track[self->next_span++];
+    *buffer_length = span.dur * BYTES_PER_SAMPLE;
+    uint8_t octave1 = span.note[0] / 12; // 0..10
+    uint8_t octave2 = span.note[1] / 12; // 0..10
+    int32_t base_freq1 = notes[span.note[0] % 12];
+    int32_t base_freq2 = notes[span.note[1] % 12];
+    int32_t sample_rate = self->sample_rate;
+
+    for (uint16_t i = 0; i < span.dur; i++) {
+        int16_t semiperiod1 = span.note[0] == SILENCE ? 0 :
+            ((base_freq1 * i * 2) / sample_rate) >> (10 - octave1);
+        int16_t semiperiod2 = span.note[1] == SILENCE ? semiperiod1 :
+            ((base_freq2 * i * 2) / sample_rate) >> (10 - octave2);
+        self->buffer[i] = ((semiperiod1 % 2 + semiperiod2 % 2) - 1) * LOUDNESS;
+    }
+    *buffer = (uint8_t *)self->buffer;
+
+    return self->next_span >= self->total_spans ?
+           GET_BUFFER_DONE : GET_BUFFER_MORE_DATA;
+}
+
+void synthio_miditrack_get_buffer_structure(synthio_miditrack_obj_t *self, bool single_channel,
+    bool *single_buffer, bool *samples_signed, uint32_t *max_buffer_length, uint8_t *spacing) {
+
+    *single_buffer = true;
+    *samples_signed = true;
+    *max_buffer_length = self->buffer_length;
+    *spacing = 1;
+}
diff --git a/shared-module/synthio/MidiTrack.h b/shared-module/synthio/MidiTrack.h
new file mode 100644
index 0000000000..bd058daaee
--- /dev/null
+++ b/shared-module/synthio/MidiTrack.h
@@ -0,0 +1,65 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2021 Artyom Skrobov
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef MICROPY_INCLUDED_SHARED_MODULE_SYNTHIO_MIDITRACK_H
+#define MICROPY_INCLUDED_SHARED_MODULE_SYNTHIO_MIDITRACK_H
+
+#include "py/obj.h"
+
+#include "shared-module/synthio/__init__.h"
+
+typedef struct {
+    uint16_t dur;
+    uint8_t note[2];
+} synthio_midi_span_t;
+
+typedef struct {
+    mp_obj_base_t base;
+    uint32_t sample_rate;
+    uint16_t *buffer;
+    uint16_t buffer_length;
+    synthio_midi_span_t *track;
+    uint16_t next_span;
+    uint16_t total_spans;
+} synthio_miditrack_obj_t;
+
+
+// These are not available from Python because it may be called in an interrupt.
+void synthio_miditrack_reset_buffer(synthio_miditrack_obj_t *self,
+    bool single_channel,
+    uint8_t channel);
+
+audioio_get_buffer_result_t synthio_miditrack_get_buffer(synthio_miditrack_obj_t *self,
+    bool single_channel,
+    uint8_t channel,
+    uint8_t **buffer,
+    uint32_t *buffer_length); // length in bytes
+
+void synthio_miditrack_get_buffer_structure(synthio_miditrack_obj_t *self, bool single_channel,
+    bool *single_buffer, bool *samples_signed,
+    uint32_t *max_buffer_length, uint8_t *spacing);
+
+#endif // MICROPY_INCLUDED_SHARED_MODULE_SYNTHIO_MIDITRACK_H
diff --git a/shared-module/synthio/__init__.c b/shared-module/synthio/__init__.c
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/shared-module/synthio/__init__.h b/shared-module/synthio/__init__.h
new file mode 100644
index 0000000000..d9d98a5341
--- /dev/null
+++ b/shared-module/synthio/__init__.h
@@ -0,0 +1,32 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2021 Artyom Skrobov
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef MICROPY_INCLUDED_SHARED_MODULE_SYNTHIO__INIT__H
+#define MICROPY_INCLUDED_SHARED_MODULE_SYNTHIO__INIT__H
+
+#include "shared-module/audiocore/__init__.h"
+
+#endif  // MICROPY_INCLUDED_SHARED_MODULE_SYNTHIO__INIT__H
diff --git a/tests/circuitpython-manual/audiocore/single-track.midi b/tests/circuitpython-manual/audiocore/single-track.midi
new file mode 100755
index 0000000000..3b3dcea822
Binary files /dev/null and b/tests/circuitpython-manual/audiocore/single-track.midi differ