Teach music? Check out Chord Dice ($12.95, chorddice.com), a set of dice that lets you have fun explaining (or learning) theory. The makers of Chord Dice have a simple mantra: Music should be simple and fun, and exist for everyone. Five sixsided dice display chords and their relationship to their root key (here, G major); just roll, form the chords, and play the song that you just constructed. If you don’t know how to play the chords, download the accompanying tab dictionary. According to the company, “if you want to rock, just roll.”