Boomwhackers Octavator Tube Caps Boomwhacker Instrument sets are an entertaining, percussive way to teach children about notes Boomwhackers feature tubes that are clearly marked with each note, and may be used in sets or to teach songs Boomwhackers are available in sets of 8 Note Diatonic (BWDG), 7 Note Diatonic Bass (BWJG), 6 Note Pentatonic (BWPG), 5 Note Sharps / Flats (BWCG), 5 Note Bass Sharps / Flats (BWKG) or 12 Note Chromatic Set (BWCG) Put one of these caps on the end of a Boomwhacker tube and you'll lower the tone by a full octave! Play the tubes as usual or hold them vertically and tap on the floor as a stamping tube Place on the higher-octave Boomwhacker tubes to create the same tones as the bass octave tubes