The app is good for performers who cannot find the right music for their key. And for others, it is just HILARIOUS to hear your favorite song in a different key! Two simple steps in the app: 1. Select a song from your iTunes library 2. After the song is processed, you can then change the pitch of the song with the slider. ZTX LE Time Stretch/Pitch Shift technology licensed from Zynaptiq GmbH, http://www.zynaptiq.com/ztx(c) Zynaptiq GmbH This is the free version of Pitch Changer.