The idea for this type of tuned tongue drum set has been around for some time. Reinhold Banek and Jon Scoville featured it in their seminal book Sound Design, and gave it the name I’m using here, Square Boos. Going back further, the idea is closely related to the bamboo instrument that Harry Partch called Boos. In the Banek/Scoville model that I have followed, each drum in the set is an elongated wooden box, open at one end, with a single tongue formed by a pair of parallel cuts from the front of the top board. The air resonance of the box-like enclosure is tuned to agree with the tongue pitch, and this the key to the saturated, bubbly tone. The instrument shown her has twenty individual drums tuned chromatically over a range of a twelfth.
In the audio clip, the Square Boos are accompanied by Cubist Bass.