Work in progress Django App.
As a guitarist wanting to learn certain songs that are in much lower tunings than my guitar might currently be set up for, I often download mp3s and pitchshift them in audacity, eliminating the need to retune my instrument.
This app is meant to streamline the process, simply allowing the user to enter a link to a youtube video of a song, enter how many semitones they want to pitchshift the audio and then play it back in the browser.