Jon, I just finished with a production of WW at the theatre I music direct at. The Keyboard I book is mostly piano (many parts double the PC score), but also includes harpsichord, electric piano, bells, and optional strings. The Keyboard II book contain mostly mallet percussion (Xylophone, Glockenspiel) and aux instruments (Strings, Guitar, Elec. Piano, Gong, Video Game SFX, Etc.). There is only one drum book and it can accomplished completely using set and opt. castinets. Hope this helps! Derek