The set list menu could be upgraded with some new features for those of us that use Sonar as a live performance tool.
1. Ability to highlight text with different colors. Would make searching the list for rock songs, ballads, etc quicker if you colorize the song title.
2. Add several columns that you could click to resort the the play list. That way you could quickly rearrange the set list for certain playlist changes on the fly.
You might consider making a specific user interface for performance play back since most users would not need recording or editing ability during live performance playback.