MIDI Synthesis / DeepBach notes

midi_synthesis.md

Synthesize a MIDI file to WAV from the command line using FluidSynth:

fluidsynth -F output.wav soundfont.sf2 input.mid

Some popular SoundFonts: GeneralUser GS, Fluid R3 GM, some others.

DeepBach uses the Python music21 library for MIDI parsing, but only supports monophonic MIDI (it throws 'Chord' object has no attribute 'pitch' if you give it a polyphonic MIDI file). The patch here lets it use polyphonic MIDI by arbitrarily using the first pitch in a chord.

polyphonic.diff

diff --git a/data_utils.py b/data_utils.py
index 4e3734e..d67e6f3 100644
--- a/data_utils.py
+++ b/data_utils.py
@@ -90,14 +90,20 @@ def part_to_list(part):
     while i < length:
         if j < num_notes - 1:
             if list_notes[j + 1].offset > i / SUBDIVISION:
-                t[i, :] = [list_notes[j].pitch.midi, is_articulated]
+                if hasattr(list_notes[j], 'pitch'):
+                    t[i, :] = [list_notes[j].pitch.midi, is_articulated]
+                elif hasattr(list_notes[j], 'pitches'):
+                    t[i, :] = [list_notes[j].pitches[0].midi, is_articulated]
                 i += 1
                 is_articulated = False
             else:
                 j += 1
                 is_articulated = True
         else:
-            t[i, :] = [list_notes[j].pitch.midi, is_articulated]
+            if hasattr(list_notes[j], 'pitch'):
+                t[i, :] = [list_notes[j].pitch.midi, is_articulated]
+            elif hasattr(list_notes[j], 'pitches'):
+                t[i, :] = [list_notes[j].pitches[0].midi, is_articulated]
             i += 1
             is_articulated = False
     return t