PySynth is a simple music synthesizer for Python 2 or 3. The goal is not to produce many different sounds, but to have scripts that can turn ABC notation or MIDI files into a WAV file without too much tinkering.
The current release of the synthesizer can only play one note at a time. (Although successive notes can overlap in PySynth B and S, but not A.) However, two output files can be mixed together to get stereo sound.
| Synth | Synthesis method | Approximate timbre | Note decay | Needs NumPy? |
|---|---|---|---|---|
| A | additive (3 sine waves) | flute, organ, piano | variable (depends on note length) | no |
| B | additive (5 sine waves) | acoustic piano | medium | yes |
| C | subtractive (sawtooth wave) | bowed string, analog synth pad | none | no |
| D | subtractive (square wave) | woodwind, analog synth lead | none | no |
| E | FM/phase modulation (6 sine waves) | DX7 Rhodes piano | medium | yes |
| F | subtractive (triangle wave) | flute, single reed | none | no |
| P | subtractive (white noise) | untuned percussion hit | very fast | no |
| S | Karplus-Strong (physical modeling) | plucked string, guitar, koto | fast | yes |
| beeper | additive | Nokia phone ringtone | none | no |
| samp | sampler | Salamander Grand Piano | medium | yes |
There are also three synthesizers which can be played in real-time, e.g. from a MIDI keyboard or other MIDI source. They all require pyaudio and mido:
- multi_synth.py: polyphonic additive synthesizer with 8-note polyphony by default
- multi_wave.py: polyphonic wavetable synthesizer with 12-note polyphony by default
- midi_synth.py: simple monophonic additive synthesizer
Multi_synth.py and midi_synth.py use three sine waves like PySynth A and an exponential decay like PySynth B, so they sound very similar to PySynth A and B.
There is also a helper script, midi_play.py, which can be used to send a MIDI file to these synthesizers.
The script make_wavetable.py creates a wavetable with 256 samples and 32 waveforms which is used by multi_wave.py by default.
If you hear crackling audio from these scripts, you might want to
- quit other applications, especially web browsers.
- increase audio buffer size (BSIZE) in the scripts or reduce maximum polyphony (MAXPOLY).
- make sure you are running a recent Python version, because Python performance tends to improve with each release.
Clone the repository:
git clone git@github.com:mdoege/PySynth.git
or
git clone https://github.com/mdoege/PySynth.git
Enter the directory (cd PySynth) and run
python -m pip install .
Basic usage:
import pysynth as ps
test = (('c', 4), ('e', 4), ('g', 4),
('c5', -2), ('e6', 8), ('d#6', 2))
ps.make_wav(test, fn = "test.wav")More advanced usage:
import pysynth_b as psb # a, b, e, and s variants available
''' (note, duration)
Note name (a to g), then optionally a '#' for sharp or
'b' for flat, then optionally the octave (defaults to 4).
An asterisk at the end means to play the note a little
louder. Duration: 4 is a quarter note, -4 is a dotted
quarter note, etc.'''
song = (
('c', 4), ('c*', 4), ('eb', 4),
('g#', 4), ('g*', 2), ('g5', 4),
('g5*', 4), ('r', 4), ('e5', 16),
('f5', 16), ('e5', 16), ('d5', 16),
('e5*', 4)
)
# Beats per minute (bpm) is really quarters per minute here
psb.make_wav(song, fn = "danube.wav", leg_stac = .7, bpm = 180)Read ABC file and output WAV:
python3 read_abc.py straw.abc
More documentation and examples at the PySynth homepage.