Wak-a-Tube C major Scale Bass Octave SetBasic bass octave starter set. Pitches included are: C28, D30, E32, F33, G35, A37, and B39. Wak a Tubes are brightly coloured percussion instruments made from different lengths of plastic tubing. Theyre fun and easy for musicians of all ages to play simply whack them against a hard surface, hit them against each other, or lay them out on a flat surface and strike them with beaters. Playing Wak a Tubes in a group is a great way to learn about teamwork