Each sub-app has links to the note taking app allowing you to jot down notes regardless of what you are doing at the time.
Tons of information all in one place. Store documents and sheet music for a variety of gigs all in one place. A very useful utility for school based iPad music classes.
Quickly send recordings via email to a teacher or parent.
Being able to record video as well as audio would be a nice addition during practices for some students.