PySynth is a simple music synthesizer written in Python. The goal is not to produce many different sounds, but to have scripts that can turn ABC notation into a WAV file without too much tinkering.
There are three variants: PySynth A is faster, only depends on Python 2, and sounds like a cross between a flute and organ. PySynth B is more complex in sound and needs NumPy. It's supposed to be a little closer to a piano. Finally, PySynth S is more comparable to a guitar, banjo, or harpsichord, depending on note length and pitch.
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.
Read ABC file and output WAV:
python read_abc.py straw.abc
As a module from the Python interpreter:
from pysynth_b import * make_wav(song, fn = "danube.wav", leg_stac = .7, bpm = 180)
More documentation and examples at the PySynth homepage.