These brightly colored, tuned percussion tubes are great for teaching students of any age about sound. When whacked against your knee or the floor each produces a particular note. The longer the tube, the lower the note. Each tube is color-coded and labeled with its precise note. When the tube is closed at one end with a cap, the note shifts an octave lower. Boomwhackers were invented by Craig Ramsell when he noticed that cardboard tubes from wrapping paper could be used to produce music. These tubes are amazing, loads of fun and very educational. Put a class set together and compose your next science sound lesson!