Notezilla is a neat iPad app that features sheet music synchronized to recordings. As you listen the recording the sheet music scrolls along. You can choose to see a red line moving to indicate the notes being played or choose to not see the red line at all. You can select sections of a recording to hear and see in your Notezilla library.
For the student who is learning to play a new selection Notezilla provides an option to slow the tempo for a recording could be helpful. Students can also choose to turn on or turn off the display of sheet music for specific instruments heard in a recording. Being able to see and hear where their instruments fit into the overall score of a piece could help students be better prepared for the transition from practicing in isolation to rehearsing with a full orchestra or band.