Philadelphia's Academy of Music is the second stop for the national tour of the eagerly-awaited Disney's High School Musical (July 11-22). Adapted by David Simpatico from the hugely popular Disney Channel film, the show is the story of a high school basketball player who defies his cliquish friends to star in the school musical with an intellectually-gifted female lead. Also, Theatre Horizon presents the family-friendly Broadway musical Once on This Island (July 1-15), featuring a book and lyrics by Lynn Ahrens and music by Stephen Flaherty. This beloved tale of star-crossed lovers who try to overcome prejudice and racism is helmed by Horizon artistic director Matthew Decker.