This is a bit of a general suggestion, but several major colleges and universities all across the nation host annual "band days" in which local high schools can come out, learn a new song and routine, and perform with several other bands on the field!
For instance, one of our favorite option personally is the University of Missouri's Mizzou Band Days, an event in which you spend the day practicing with the pros, then hit Faurot Field with hundreds of other students and strut your stuff in front of the massive football-game attending crowd!
Examples:
Birmingham Southern University
University of California, Los Angeles
