Real-Time Signal Processing in Python

Did you know computers are fast enough to let you write Python code for guitar effects?

http://bastibe.de/2012-11-02-real-time-signal-processing-in-python.html

I am curious how far this can be pushed!  If we can write python guitar effects and synthesizers, what about these question...

Instrument builders: Shouldn't it be possible to help musicians craft the specific sound they want?

Instrument players: Is it possible to give you the power to perfect your sound through code?