A free and easy tool to change song pitch and tempo

I've written a small program that might be helpful for other users of this website. It provides similar functionality to the amazing slow downer, but is free software:

a_to_c.py is a script to convert songs from one pitch to the other, and optionally change their tempo.

Get it here: https://github.com/Sjlver/a_to_c

Comments and suggestions are welcome. If you're a developer, you can also add a star on GitHub, or send me pull requests.