diff --git a/NeoTrellis_M4_MIDI_Synth/events.py b/NeoTrellis_M4_MIDI_Synth/events.py
new file mode 100644
index 00000000..550cddf1
--- /dev/null
+++ b/NeoTrellis_M4_MIDI_Synth/events.py
@@ -0,0 +1,409 @@
+"""
+NeoTrellis M4 Express MIDI synth
+
+Adafruit invests time and resources providing this open source code.
+Please support Adafruit and open source hardware by purchasing
+products from Adafruit!
+
+Written by Dave Astels for Adafruit Industries
+Copyright (c) 2018 Adafruit Industries
+Licensed under the MIT license.
+
+All text above must be included in any redistribution.
+"""
+
+# Events as defined in http://www.music.mcgill.ca/~ich/classes/mumt306/StandardMIDIfileformat.html
+# pylint: disable=unused-argument,no-self-use
+
+
+class Event(object):
+
+    def __init__(self, delta_time):
+        self._delta_time = delta_time
+
+    @property
+    def time(self):
+        return self._delta_time
+
+    def execute(self, sequencer):
+        return False
+
+
+class F0SysexEvent(Event):
+    def __init__(self, delta_time, data):
+        Event.__init__(self, delta_time)
+        self._data = data
+
+
+class F7SysexEvent(Event):
+
+    def __init__(self, delta_time, data):
+        Event.__init__(self, delta_time)
+        self._data = data
+
+class MetaEvent(Event):
+
+    def __init__(self, delta_time):
+        Event.__init__(self, delta_time)
+
+
+class SequenceNumberMetaEvent(MetaEvent):
+
+    def __init__(self, delta_time, sequence_number):
+        MetaEvent.__init__(self, delta_time)
+        self._sequence_number = sequence_number
+
+    def __str__(self):
+        return '%d : Sequence Number : %d' % (self._delta_time, self._sequence_number)
+
+
+class TextMetaEvent(MetaEvent):
+    def __init__(self, delta_time, text):
+        MetaEvent.__init__(self, delta_time)
+        self._text = text
+
+    def __str__(self):
+        return '%d : Text : %s' % (self._delta_time, self._text)
+
+
+class CopyrightMetaEvent(MetaEvent):
+
+    def __init__(self, delta_time, copyright_notice):
+        MetaEvent.__init__(self, delta_time)
+        self._copyright_notice = copyright_notice
+
+    def __str__(self):
+        return '%d : Copyright : %s' % (self._delta_time, self._copyright_notice)
+
+
+class TrackNameMetaEvent(MetaEvent):
+    def __init__(self, delta_time, track_name):
+        MetaEvent.__init__(self, delta_time)
+        self._track_name = track_name
+
+    def __str__(self):
+        return '%d : Track Name : %s' % (self._delta_time, self._track_name)
+
+
+class InstrumentNameMetaEvent(MetaEvent):
+
+    def __init__(self, delta_time, instrument_name):
+        MetaEvent.__init__(self, delta_time)
+        self._instrument_name = instrument_name
+
+    def __str__(self):
+        return '%d : Instrument Name : %s' % (self._delta_time, self._instrument_name)
+
+
+class LyricMetaEvent(MetaEvent):
+
+    def __init__(self, delta_time, lyric):
+        MetaEvent.__init__(self, delta_time)
+        self._lyric = lyric
+
+    def __str__(self):
+        return '%d : Lyric : %s' % (self._delta_time, self._lyric)
+
+
+class MarkerMetaEvent(MetaEvent):
+
+    def __init__(self, delta_time, marker):
+        MetaEvent.__init__(self, delta_time)
+        self._marker = marker
+
+    def __str__(self):
+        return '%d : Marker : %s' % (self._delta_time, self._marker)
+
+
+class CuePointMetaEvent(MetaEvent):
+
+    def __init__(self, delta_time, cue):
+        MetaEvent.__init__(self, delta_time)
+        self._cue = cue
+
+    def __str__(self):
+        return '%d : Cue : %s' % (self._delta_time, self._cue)
+
+
+class ChannelPrefixMetaEvent(MetaEvent):
+
+    def __init__(self, delta_time, channel):
+        MetaEvent.__init__(self, delta_time)
+        self._channel = channel
+
+    def __str__(self):
+        return '%d: Channel Prefix : %d' % (self._delta_time, self._channel)
+
+
+class EndOfTrackMetaEvent(MetaEvent):
+
+    def __init__(self, delta_time):
+        MetaEvent.__init__(self, delta_time)
+
+    def __str__(self):
+        return '%d: End Of Track' % (self._delta_time)
+
+    def execute(self, sequencer):
+        sequencer.end_track()
+        return True
+
+
+class SetTempoMetaEvent(MetaEvent):
+
+    def __init__(self, delta_time, tempo):
+        MetaEvent.__init__(self, delta_time)
+        self._tempo = tempo
+
+    def __str__(self):
+        return '%d: Set Tempo : %d' % (self._delta_time, self._tempo)
+
+    def execute(self, sequencer):
+        sequencer.set_tempo(self._tempo)
+        return False
+
+
+class SmpteOffsetMetaEvent(MetaEvent):
+
+    def __init__(self, delta_time, hour, minute, second, fr, rr):
+        MetaEvent.__init__(self, delta_time)
+        self._hour = hour
+        self._minute = minute
+        self._second = second
+        self._fr = fr
+        self._rr = rr
+
+    def __str__(self):
+        return '%d : SMPTE Offset : %02d:%02d:%02d %d %d' % (self._delta_time,
+                                                             self._hour,
+                                                             self._minute,
+                                                             self._second,
+                                                             self._fr,
+                                                             self._rr)
+
+
+class TimeSignatureMetaEvent(MetaEvent):
+
+    def __init__(self, delta_time, nn, dd, cc, bb):
+        MetaEvent.__init__(self, delta_time)
+        self._numerator = nn
+        self._denominator = dd
+        self._cc = cc
+        self._bb = bb
+
+    def __str__(self):
+        return '%d : Time Signature : %d %d %d %d' % (self._delta_time,
+                                                      self._numerator,
+                                                      self._denominator,
+                                                      self._cc,
+                                                      self._bb)
+
+    def execute(self, sequencer):
+        sequencer.set_time_signature(self._numerator, self._denominator, self._cc)
+        return False
+
+
+class KeySignatureMetaEvent(MetaEvent):
+
+    def __init__(self, delta_time, sf, mi):
+        MetaEvent.__init__(self, delta_time)
+        self._sf = sf
+        self._mi = mi
+
+    def __str__(self):
+        return '%d : Key Signature : %d %d' % (self._delta_time, self._sf, self._mi)
+
+
+class SequencerSpecificMetaEvent(MetaEvent):
+
+    def __init__(self, delta_time, data):
+        MetaEvent.__init__(self, delta_time)
+        self._data = data
+
+
+class MidiEvent(Event):
+
+    def __init__(self, delta_time, channel):
+        Event.__init__(self, delta_time)
+        self._channel = channel
+
+
+class NoteOffEvent(MidiEvent):
+
+    def __init__(self, delta_time, channel, key, velocity):
+        MidiEvent.__init__(self, delta_time, channel)
+        self._key = key
+        self._velocity = velocity
+
+    def __str__(self):
+        return '%d : Note Off : key %d, velocity %d' % (self._delta_time,
+                                                        self._key,
+                                                        self._velocity)
+
+    def execute(self, sequencer):
+        sequencer.note_off(self._key, self._velocity)
+        return False
+
+
+class NoteOnEvent(MidiEvent):
+
+    def __init__(self, delta_time, channel, key, velocity):
+        MidiEvent.__init__(self, delta_time, channel)
+        self._key = key
+        self._velocity = velocity
+
+    def __str__(self):
+        return '%d : Note On : key %d, velocity %d' % (self._delta_time,
+                                                       self._key,
+                                                       self._velocity)
+
+    def execute(self, sequencer):
+        sequencer.note_on(self._key, self._velocity)
+        return False
+
+
+class PolyphonicKeyPressureEvent(MidiEvent):
+
+    def __init__(self, delta_time, channel, key, pressure):
+        MidiEvent.__init__(self, delta_time, channel)
+        self._key = key
+        self._pressure = pressure
+
+    def __str__(self):
+        return '%d : Poly Key Pressure : key %d, velocity %d' % (self._delta_time,
+                                                                 self._key,
+                                                                 self._pressure)
+
+
+class ControlChangeEvent(MidiEvent):
+
+    def __init__(self, delta_time, channel, controller, value):
+        MidiEvent.__init__(self, delta_time, channel)
+        self._controller = controller
+        self._value = value
+
+    def __str__(self):
+        return '%d : Control Change : controller %d, value %d' % (self._delta_time,
+                                                                  self._controller,
+                                                                  self._value)
+
+
+
+class ProgramChangeEvent(MidiEvent):
+
+    def __init__(self, delta_time, channel, program_number):
+        MidiEvent.__init__(self, delta_time, channel)
+        self._program_number = program_number
+
+    def __str__(self):
+        return '%d : Program Change : program %d' % (self._delta_time,
+                                                     self._program_number)
+
+class ChannelPressureEvent(MidiEvent):
+
+    def __init__(self, delta_time, channel, pressure):
+        MidiEvent.__init__(self, delta_time, channel)
+        self._pressure = pressure
+
+    def __str__(self):
+        return '%d : Channel Pressure : %d' % (self._delta_time, self._channel)
+
+class PitchWheelChangeEvent(MidiEvent):
+
+    def __init__(self, delta_time, channel, value):
+        MidiEvent.__init__(self, delta_time, channel)
+        self._value = value
+
+    def __str__(self):
+        return '%d : Pitch Wheel Change : %d' % (self._delta_time, self._value)
+
+
+class SystemExclusiveEvent(MidiEvent):
+
+    def __init__(self, delta_time, channel, data):
+        MidiEvent.__init__(self, delta_time, channel)
+        self._data = data
+
+
+class SongPositionPointerEvent(MidiEvent):
+
+    def __init__(self, delta_time, beats):
+        MidiEvent.__init__(self, delta_time, None)
+        self._beats = beats
+
+    def __str__(self):
+        return '%d: SongPositionPointerEvent(beats %d)' % (self._delta_time,
+                                                           self._beats)
+
+
+class SongSelectEvent(MidiEvent):
+
+    def __init__(self, delta_time, song):
+        MidiEvent.__init__(self, delta_time, None)
+        self._song = song
+
+    def __str__(self):
+        return '%d: SongSelectEvent(song %d)' % (self._delta_time,
+                                                 self._song)
+
+
+class TuneRequestEvent(MidiEvent):
+
+    def __init__(self, delta_time):
+        MidiEvent.__init__(self, delta_time, None)
+
+    def __str__(self):
+        return '%d : Tune Request' % (self._delta_time)
+
+
+class TimingClockEvent(MidiEvent):
+
+    def __init__(self, delta_time):
+        MidiEvent.__init__(self, delta_time, None)
+
+    def __str__(self):
+        return '%d : Timing Clock' % (self._delta_time)
+
+
+class StartEvent(MidiEvent):
+
+    def __init__(self, delta_time):
+        MidiEvent.__init__(self, delta_time, None)
+
+    def __str__(self):
+        return '%d : Start' % (self._delta_time)
+
+
+class ContinueEvent(MidiEvent):
+
+    def __init__(self, delta_time):
+        MidiEvent.__init__(self, delta_time, None)
+
+    def __str__(self):
+        return '%d : Continue' % (self._delta_time)
+
+
+class StopEvent(MidiEvent):
+
+    def __init__(self, delta_time):
+        MidiEvent.__init__(self, delta_time, None)
+
+    def __str__(self):
+        return '%d : Stop' % (self._delta_time)
+
+
+class ActiveSensingEvent(MidiEvent):
+
+    def __init__(self, delta_time):
+        MidiEvent.__init__(self, delta_time, None)
+
+    def __str__(self):
+        return '%d : Active Sensing' % (self._delta_time)
+
+
+class ResetEvent(MidiEvent):
+
+    def __init__(self, delta_time):
+        MidiEvent.__init__(self, delta_time, None)
+
+    def __str__(self):
+        return '%d : Reset' % (self._delta_time)
diff --git a/NeoTrellis_M4_MIDI_Synth/header.py b/NeoTrellis_M4_MIDI_Synth/header.py
new file mode 100644
index 00000000..f667ed5a
--- /dev/null
+++ b/NeoTrellis_M4_MIDI_Synth/header.py
@@ -0,0 +1,43 @@
+"""
+NeoTrellis M4 Express MIDI synth
+
+Adafruit invests time and resources providing this open source code.
+Please support Adafruit and open source hardware by purchasing
+products from Adafruit!
+
+Written by Dave Astels for Adafruit Industries
+Copyright (c) 2018 Adafruit Industries
+Licensed under the MIT license.
+
+All text above must be included in any redistribution.
+"""
+
+class MidiHeader(object):
+
+    def __init__(self,
+                 midi_format,
+                 number_of_tracks,
+                 ticks_per_frame,
+                 negative_SMPTE_format,
+                 ticks_per_quarternote):
+        self._format = midi_format
+        self._number_of_tracks = number_of_tracks
+        self._ticks_per_frame = ticks_per_frame
+        self._negative_SMPTE_format = negative_SMPTE_format
+        self._ticks_per_quarternote = ticks_per_quarternote
+
+    @property
+    def number_of_tracks(self):
+        return self._number_of_tracks
+
+    def __str__(self):
+        format_string = ('Header - format: {0}, '
+                         'track count: {1}, '
+                         'ticks per frame: {2}, '
+                         'SMPTE: {3}, '
+                         'ticks per quarternote: {4}')
+        return format_string.format(self._format,
+                                    self._number_of_tracks,
+                                    self._ticks_per_frame,
+                                    self._negative_SMPTE_format,
+                                    self._ticks_per_quarternote)
diff --git a/NeoTrellis_M4_MIDI_Synth/main.py b/NeoTrellis_M4_MIDI_Synth/main.py
new file mode 100644
index 00000000..d1cb2876
--- /dev/null
+++ b/NeoTrellis_M4_MIDI_Synth/main.py
@@ -0,0 +1,65 @@
+"""
+NeoTrellis M4 Express MIDI synth
+
+Adafruit invests time and resources providing this open source code.
+Please support Adafruit and open source hardware by purchasing
+products from Adafruit!
+
+Written by Dave Astels for Adafruit Industries
+Copyright (c) 2018 Adafruit Industries
+Licensed under the MIT license.
+
+All text above must be included in any redistribution.
+"""
+
+import os
+import parser
+import sequencer
+import synth
+import adafruit_trellism4
+
+trellis = adafruit_trellism4.TrellisM4Express(rotation=0)
+trellis.pixels.brightness = 0.1
+trellis.pixels.fill(0)
+
+syn = synth.Synth()
+seq = sequencer.Sequencer(syn)
+p = parser.MidiParser()
+
+voices = sorted([f.split('.')[0] for f in os.listdir('/samples') if f.endswith('.txt')])
+tunes = sorted([f for f in os.listdir('/midi') if f.endswith('.mid')])
+
+selected_voice = None
+
+def reset_voice_buttons():
+    for i in range(len(voices)):
+        trellis.pixels[(i, 0)] = 0x0000FF
+
+def reset_tune_buttons():
+    for i in range(len(tunes)):
+        trellis.pixels[(i % 8, (i // 8) + 1)] = 0x00FF00
+
+current_press = set()
+reset_voice_buttons()
+reset_tune_buttons()
+
+while True:
+    pressed = set(trellis.pressed_keys)
+    just_pressed = pressed - current_press
+    for down in just_pressed:
+        if down[1] == 0:
+            if down[0] < len(voices):                  # a voice selection
+                selected_voice = down[0]
+                reset_voice_buttons()
+                trellis.pixels[down] = 0xFFFFFF
+                syn.voice = voices[selected_voice]
+        else:
+            tune_index = (down[1] - 1) * 8 + down[0]
+            if tune_index < len(tunes) and selected_voice is not None:
+                trellis.pixels[down] = 0xFFFFFF
+                header, tracks = p.parse('/midi/' + tunes[tune_index])
+                for track in tracks:
+                    seq.play(track)
+                reset_tune_buttons()
+
+    current_press = pressed
diff --git a/NeoTrellis_M4_MIDI_Synth/parser.py b/NeoTrellis_M4_MIDI_Synth/parser.py
new file mode 100644
index 00000000..26d2298e
--- /dev/null
+++ b/NeoTrellis_M4_MIDI_Synth/parser.py
@@ -0,0 +1,257 @@
+"""
+NeoTrellis M4 Express MIDI synth
+
+Adafruit invests time and resources providing this open source code.
+Please support Adafruit and open source hardware by purchasing
+products from Adafruit!
+
+Written by Dave Astels for Adafruit Industries
+Copyright (c) 2018 Adafruit Industries
+Licensed under the MIT license.
+
+All text above must be included in any redistribution.
+"""
+
+# pylint: disable=no-self-use,too-many-return-statements,too-many-branches,inconsistent-return-statements
+
+import header
+import events
+
+def log(txt):
+    print(txt)
+    #pass
+
+class MidiParser(object):
+
+    def __init__(self):
+        pass
+
+    def _as_8(self, d):
+        return d[0]
+
+    def _as_16(self, d):
+        return (d[0] << 8) | d[1]
+
+    def _as_24(self, d):
+        return (d[0] << 16) | (d[1] << 8) | d[2]
+
+    def _as_32(self, d):
+        return (d[0] << 24) | (d[1] << 16) | (d[2] << 8) | d[3]
+
+    def _as_str(self, d):
+        return str(d, encoding='utf8')
+
+    def _read_bytes(self, f, count):
+        val = f.read(count)
+        return val
+
+    def _read_1_byte(self, f):
+        return self._read_bytes(f, 1)
+
+    def _read_2_bytes(self, f):
+        return self._read_bytes(f, 2)
+
+    def _read_3_bytes(self, f):
+        return self._read_bytes(f, 3)
+
+    def _read_4_bytes(self, f):
+        return self._read_bytes(f, 4)
+
+    def _read_8(self, f):
+        return self._as_8(self._read_bytes(f, 1))
+
+    def _read_16(self, f):
+        return self._as_16(self._read_bytes(f, 2))
+
+    def _read_24(self, f):
+        return self._as_24(self._read_bytes(f, 3))
+
+    def _read_32(self, f):
+        return self._as_32(self._read_bytes(f, 4))
+
+    def _parse_header(self, f):
+        if self._read_4_bytes(f) != b'MThd':
+            return None
+        if self._read_32(f) != 6:
+            return None
+        midi_format = self._read_16(f)
+        midi_number_of_tracks = self._read_16(f)
+        d = self._read_2_bytes(f)
+        if d[0] & 0x80:
+            ticks_per_frame = d[1]
+            negative_SMPTE_format = d[0] & 0x7F
+            ticks_per_quarternote = None
+        else:
+            ticks_per_frame = None
+            negative_SMPTE_format = None
+            ticks_per_quarternote = (d[0] << 8) | d[1]
+        return header.MidiHeader(midi_format,
+                                 midi_number_of_tracks,
+                                 ticks_per_frame,
+                                 negative_SMPTE_format,
+                                 ticks_per_quarternote)
+
+    def _parse_variable_length_number(self, f):
+        value = self._read_8(f)
+        if not value & 0x80:
+            return value
+        value &= 0x7F
+        b = self._read_8(f)
+        while b & 0x80:
+            value = (value << 7) | (b & 0x7F)
+            b = self._read_8(f)
+        return (value << 7) | b
+
+    def _parse_F0_sysex_event(self, delta_time, f):
+        length = self._parse_variable_length_number(f)
+        data = self._read_bytes(f, length)
+        return events.F0SysexEvent(delta_time, data)
+
+    def _parse_F7_sysex_event(self, f, delta_time):
+        length = self._parse_variable_length_number(f)
+        data = self._read_bytes(f, length)
+        return events.F7SysexEvent(delta_time, data)
+
+    def _parse_meta_event(self, f, delta_time):
+        meta_event_type = self._read_8(f)
+        length = self._parse_variable_length_number(f)
+        data = self._read_bytes(f, length)
+        if meta_event_type == 0x00:
+            return events.SequenceNumberMetaEvent(delta_time, self._as_16(data))
+        elif meta_event_type == 0x01:
+            return events.TextMetaEvent(delta_time, self._as_str(data))
+        elif meta_event_type == 0x02:
+            return events.CopyrightMetaEvent(delta_time, self._as_str(data))
+        elif meta_event_type == 0x03:
+            return events.TrackNameMetaEvent(delta_time, self._as_str(data))
+        elif meta_event_type == 0x04:
+            return events.InstrumentNameMetaEvent(delta_time, self._as_str(data))
+        elif meta_event_type == 0x05:
+            return events.LyricMetaEvent(delta_time, self._as_str(data))
+        elif meta_event_type == 0x06:
+            return events.MarkerMetaEvent(delta_time, self._as_str(data))
+        elif meta_event_type == 0x07:
+            return events.CuePointMetaEvent(delta_time, self._as_str(data))
+        elif meta_event_type == 0x20:
+            if length != 0x01:
+                return None
+            track = self._as_8(data)
+            if track > 15:
+                return None
+            return events.ChannelPrefixMetaEvent(delta_time, track)
+        elif meta_event_type == 0x2F:
+            if length != 0:
+                return None
+            return events.EndOfTrackMetaEvent(delta_time)
+        elif meta_event_type == 0x51:
+            if length != 3:
+                return None
+            return events.SetTempoMetaEvent(delta_time, self._as_24(data))
+        elif meta_event_type == 0x54:
+            if length != 5:
+                return None
+            return events.SmpteOffsetMetaEvent(delta_time, data[0], data[1],
+                                               data[2], data[3], data[4])
+        elif meta_event_type == 0x58:
+            if length != 4:
+                return None
+            return events.TimeSignatureMetaEvent(delta_time, data[0], data[1],
+                                                 data[2], data[3])
+        elif meta_event_type == 0x59:
+            if length != 2:
+                return None
+            return events.KeySignatureMetaEvent(delta_time, data[0], data[1])
+        elif meta_event_type == 0x7F:
+            return events.SequencerSpecificMetaEvent(delta_time, data)
+
+    def _parse_midi_event(self, f, delta_time, status):
+        if status & 0xF0 != 0xF0:
+            command = (status & 0xF0) >> 4
+            channel = status & 0x0F
+            data_1 = self._read_8(f) & 0x7F
+            data_2 = 0
+            if command in [8, 9, 10, 11, 14]:
+                data_2 = self._read_8(f) & 0x7F
+            if command == 8:
+                return events.NoteOffEvent(delta_time, channel, data_1, data_2)
+            elif command == 9:
+                if data_2 == 0:
+                    return events.NoteOffEvent(delta_time, channel, data_1, data_2)
+                return events.NoteOnEvent(delta_time, channel, data_1, data_2)
+            elif command == 10:
+                return events.PolyphonicKeyPressureEvent(delta_time, channel, data_1, data_2)
+            elif command == 11:
+                return events.ControlChangeEvent(delta_time, channel, data_1, data_2)
+            elif command == 12:
+                return events.ProgramChangeEvent(delta_time, channel, data_1)
+            elif command == 13:
+                return events.ChannelPressureEvent(delta_time, channel, data_1)
+            elif command == 14:
+                return events.PitchWheelChangeEvent(delta_time, channel, (data_2 << 7) | data_1)
+            return None
+        message_id = status & 0x0F
+        if message_id == 0:
+            manufacturer_id = self._read_8(f)
+            data = []
+            d = self._read_8(f)
+            while d != 0xF7:
+                data.append(d)
+                d = self._read_8(f)
+            return events.SystemExclusiveEvent(delta_time, manufacturer_id, data)
+        elif message_id == 2:
+            lo7 = self._read_8(f)
+            hi7 = self._read_8(f)
+            return events.SongPositionPointerEvent(delta_time, (hi7 << 7) | lo7)
+        elif message_id == 3:
+            return events.SongSelectEvent(delta_time, self._read_8(f))
+        elif message_id == 6:
+            return events.TuneRequestEvent(delta_time)
+        elif message_id == 8:
+            return events.TimingClockEvent(delta_time)
+        elif message_id == 10:
+            return events.StartEvent(delta_time)
+        elif message_id == 11:
+            return events.ContinueEvent(delta_time)
+        elif message_id == 12:
+            return events.StopEvent(delta_time)
+        elif message_id == 14:
+            return events.ActiveSensingEvent(delta_time)
+        elif message_id == 15:
+            return events.ResetEvent(delta_time)
+        return None
+
+    def parse_mtrk_event(self, f):
+        delta_time = self._parse_variable_length_number(f)
+        event_type = self._read_8(f)
+        if event_type == 0xF0:            #sysex event
+            event = self._parse_F0_sysex_event(f, delta_time)
+        elif event_type == 0xF7:          #sysex event
+            event = self._parse_F7_sysex_event(f, delta_time)
+        elif event_type == 0xFF:          #meta event
+            event = self._parse_meta_event(f, delta_time)
+        else:                         #regular midi event
+            event = self._parse_midi_event(f, delta_time, event_type)
+        log(event)
+        return event
+
+    def _parse_track(self, f):
+        if self._read_4_bytes(f) != b'MTrk':
+            return None
+        track_length = self._read_32(f)
+        track_data = []
+        for _ in range(track_length):
+            event = self.parse_mtrk_event(f)
+            if event is None:
+                log('Error')
+            track_data.append(event)
+            if isinstance(event, events.EndOfTrackMetaEvent):
+                return track_data
+        return track_data
+
+    def parse(self, filename):
+        with open(filename, 'rb') as f:
+            tracks = []
+            h = self._parse_header(f)
+            for _ in range(h.number_of_tracks):
+                tracks.append(self._parse_track(f))
+        return (h, tracks)
diff --git a/NeoTrellis_M4_MIDI_Synth/sequencer.py b/NeoTrellis_M4_MIDI_Synth/sequencer.py
new file mode 100644
index 00000000..5254304d
--- /dev/null
+++ b/NeoTrellis_M4_MIDI_Synth/sequencer.py
@@ -0,0 +1,62 @@
+"""
+NeoTrellis M4 Express MIDI synth
+
+Adafruit invests time and resources providing this open source code.
+Please support Adafruit and open source hardware by purchasing
+products from Adafruit!
+
+Written by Dave Astels for Adafruit Industries
+Copyright (c) 2018 Adafruit Industries
+Licensed under the MIT license.
+
+All text above must be included in any redistribution.
+"""
+
+import time
+
+class Sequencer(object):
+
+    def __init__(self, synth):
+        self._synth = synth
+        self.set_tempo(120)
+        self._numerator = 4
+        self._denominator = 2
+        self._clocks_per_metronome_click = 24
+        self.set_tempo(500000)
+        self.set_time_signature(4, 2, 24)
+
+    def _tick(self):
+        time.sleep(self._tick_size)
+
+    def play(self, track):
+        for event in track:
+            delta_time = 0
+            while event.time > delta_time:
+                delta_time += 1
+                self._tick()
+            print('Executing %s' % str(event))
+            if event.execute(self):
+                return
+
+    def set_tempo(self, tempo):
+        print('Setting tempo %d' % tempo)
+        self._tempo = tempo
+        self._tick_size = tempo / 250000000.0
+
+    def set_time_signature(self, numerator, denominator, clocks_per_metronome_click):
+        print('Setting time signature')
+        self._numerator = numerator
+        self._denominator = denominator
+        self._clocks_per_metronome_click = clocks_per_metronome_click
+
+    def note_on(self, key, velocity):
+#        print('Note on')
+        self._synth.note_on(key, velocity)
+
+    def note_off(self, key, velocity):
+#        print('Note off')
+        self._synth.note_off(key, velocity)
+
+    def end_track(self):
+        pass
+#        print('End track')
diff --git a/NeoTrellis_M4_MIDI_Synth/sound_files.zip b/NeoTrellis_M4_MIDI_Synth/sound_files.zip
new file mode 100644
index 00000000..2e6f468e
Binary files /dev/null and b/NeoTrellis_M4_MIDI_Synth/sound_files.zip differ
diff --git a/NeoTrellis_M4_MIDI_Synth/synth.py b/NeoTrellis_M4_MIDI_Synth/synth.py
new file mode 100644
index 00000000..adfe6f7d
--- /dev/null
+++ b/NeoTrellis_M4_MIDI_Synth/synth.py
@@ -0,0 +1,123 @@
+"""
+NeoTrellis M4 Express MIDI synth
+
+Adafruit invests time and resources providing this open source code.
+Please support Adafruit and open source hardware by purchasing
+products from Adafruit!
+
+Written by Dave Astels for Adafruit Industries
+Copyright (c) 2018 Adafruit Industries
+Licensed under the MIT license.
+
+All text above must be included in any redistribution.
+"""
+
+# pylint: disable=unused-argument
+
+import time
+import board
+import audioio
+
+SAMPLE_FOLDER = '/samples/'       # the name of the folder containing the samples
+VOICE_COUNT = 8
+
+def capitalize(s):
+    if not s:
+        return ''
+    return s[0].upper() + ''.join([x.lower() for x in s[1:]])
+
+
+class Synth(object):
+
+    def __init__(self):
+        self._voice_name = None
+        self._voice_file = None
+        self._samples = [None] * 128
+        self._channel_count = None
+        self._bits_per_sample = None
+        self._sample_rate = None
+        self._audio = None
+        self._mixer = None
+        self._currently_playing = [{'key': None, 'voice' : x} for x in range(VOICE_COUNT)]
+        self._voices_used = 0
+
+    def _initialize_audio(self):
+        if self._audio is None:
+            self._audio = audioio.AudioOut(board.A1)
+            self._mixer = audioio.Mixer(voice_count=VOICE_COUNT,
+                                        sample_rate=16000,
+                                        channel_count=1,
+                                        bits_per_sample=16,
+                                        samples_signed=True)
+            self._audio.play(self._mixer)
+
+    def reset(self):
+        for i in range(len(self._samples)):
+            self._samples[i] = None
+        for p in self._currently_playing:
+            p['key'] = None
+
+    @property
+    def voice(self):
+        return self._voice_name
+
+    @voice.setter
+    def voice(self, v):
+        self._initialize_audio()
+        self._voice_name = capitalize(v)
+        self._voice_file = '/samples/%s.txt' % v.lower()
+        first_note = None
+        with open(self._voice_file, "r") as f:
+            for line in f:
+                cleaned = line.strip()
+                if len(cleaned) > 0 and cleaned[0] != '#':
+                    key, filename = cleaned.split(',', 1)
+                    self._samples[int(key)] = filename.strip()
+                    if first_note is None:
+                        first_note = filename.strip()
+        sound_file = open(SAMPLE_FOLDER+first_note, 'rb')
+        wav = audioio.WaveFile(sound_file)
+        self._mixer.play(wav, voice=0, loop=False)
+        time.sleep(0.5)
+        self._mixer.stop_voice(0)
+
+    def _find_usable_voice_for(self, key):
+        if self._voices_used == VOICE_COUNT:
+            return None
+        available = None
+        for voice in self._currently_playing:
+            if voice['key'] == key:
+                return None
+            if voice['key'] is None:
+                available = voice
+        if available is not None:
+            self._voices_used += 1
+            return available
+        return None
+
+    def _find_voice_for(self, key):
+        for voice in self._currently_playing:
+            if voice['key'] == key:
+                return voice
+        return None
+
+    def note_on(self, key, velocity):
+        fname = self._samples[key]
+        if fname is not None:
+            f = open(SAMPLE_FOLDER+fname, 'rb')
+            wav = audioio.WaveFile(f)
+            voice = self._find_usable_voice_for(key)
+            if voice is not None:
+                voice['key'] = key
+                voice['file'] = f
+                self._mixer.play(wav, voice=voice['voice'], loop=False)
+
+    def note_off(self, key, velocity):
+        if self._voices_used > 0:
+            voice = self._find_voice_for(key)
+            if voice is not None:
+                self._voices_used -= 1
+                self._mixer.stop_voice(voice['voice'])
+                voice['file'].close()
+                voice['file'] = None
+                voice['key'] = None