Bad Wolf Press has seventeen fun half-hour musicals about American/World History for grades K-8. I've done the music portion of these for since-retired teachers of grades 4/5 at Polaris K-12, and the kids love them. The music CDs include the accompaniment soundtracks as well as recordings of adults singing the songs; the piano music is not included but available. (Our classroom teachers have put on these plays by themselves, but if your music teacher is helping, the piano/vocal score (written music) will be necessary.) There are roughly 10 songs per play ranging from slow to lively, and there are always a couple that cause spontaneous singing. There is not a lot of incidental music for dancing, and no stage directions in the scripts.
They also have plays for Character Education/Life Skills, Language Arts, Science & Math, and Holidays,