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Showing posts from 2010

Python musical update

Based on my procedural music project I had been working on here. I've made some improvements. Abstracted the playback some, can now play through numpy, oss, or pyaudio. The plan is to default to the best playback method, right now it just uses the first one that seems available. I did this because I got dozens of complaints about using just pyaudio. Can save audio to wave files, other formats would be nice but are not worth my time right now. It's got a few example files to give some idea of usage, but no documentation.

Google code project page is up:

Download link:

Examples include:
arpeggiated chord progression
randomly generated lead (with chorus effect)
basic example of waveform generating

If you want to take a listen without running it, I saved the audio output of examples 1 and 2...

My new musical instrument: Python

It's still very young, but here is the library I've been working on for generating music in (nothing but) Python. "" is an example of what you can do. The real purpose isn't to code your music out this way, it's intended as a backend for generating / manipulating music. My end goal is a tab-based editor that plays back with this, but I'm going to keep working on this backend and hope some brave snake wrestler comes along and has the itch to write a proper interface (and if that doesn't happen, I'll start on the interface when I feel satisfied with the backend).

The Timeline and Hit classes are just ideas right now. I'm not sure they'll stay in the form they are (I'm thinking a guitar-oriented timeline, holding fret/string/amplitude per hit, is more along the lines of what I need).

I'm also on the hunt for efficient numpy/scipy implemented effects and sound sources. I've been playing around some with generating Karplus-Stro…

Procedural music with PyAudio and NumPy

Combining two of my favorite pastimes, programming and music... This is the hacky "reduced to it's basic components" version of a library I've been working on for generating music and dealing with music theory.

Tweaking the harmonics by changing the shape of the harmonic components and ratios can produce some interesting sounds. This one only uses sine waveforms, but a square / saw generator is trivial with numpy.

It takes a second to generate, so don't turn your volume up too loud in anticipation (it may be loud).

import math
import numpy
import pyaudio
import itertools
from scipy import interpolate
from operator import itemgetter

class Note:

NOTES = ['c','c#','d','d#','e','f','f#','g','g#','a','a#','b']

def __init__(self, note, octave=4):
self.octave = octave
if isinstance(note, int):
self.index = note
self.note = Note.NOTES[note]
elif isinstance(note, st…

Javascript insort function

I recently had the need for some sorted insertion in Javascript arrays, thought I'd share this tiny bit of code:

Array.prototype.bisect = function(x, lo, hi) {
var mid;
if(typeof(lo) == 'undefined') lo = 0;
if(typeof(hi) == 'undefined') hi = this.length;
while(lo < hi) {
mid = Math.floor((lo + hi) / 2);
if(x < this[mid]) hi = mid;
else lo = mid + 1;
return lo

Array.prototype.insort = function(x) {
this.splice(this.bisect(x), 0, x);

Of course, these methods only work on an already sorted (or empty) array, so if you're using them on an array that came from elsewhere, sort it first. But once sorted, these insertions will maintain the sortedness, no need to 'push' and 'sort' every time you need to insert something into a sorted array.

(lo and hi parameters are optionally possible for the bisection method to allow restricted searches)