Boomwhackers are a real winner with kids of all ages! The tubes are perfectly tuned to different musical notes that are clearly marked on their labels. Tubes range in length from 12" to 24". Hundreds of songs can be played on Boomwhackers, play chords by combining the tones. Whack almost anything to produce tones - thigh, hand, table, chair, floor, etc. Different surfaces produce different sounds, but always the same musical pitch. 8 note diatonic C'-C" Set (upper octave).