* standard Apple Terms of Use (EULA)
http://www.apple.com/legal/internet-services/itunes/dev/stdeula

All music is free, and performers can practice through accom app, and they can improve their performance through practice that suits them by choosing various tempo and beat sounds.
You can practice not only solo songs but also various excerpts from the orchestra.

With the background function, users can practice by looking at the score and listening to the accompaniment