Tonic Eb / Key of Bb. The tonic of the bansuri is the note sounded when 3 finger holes are closed. 6 holes closed determines the key. The same flute may be referred to by either its tonic or key. Bansuri Indian flute, made of Hawaiian bamboo, plays 2 octaves, top notes take practice, 6 hole,transverse, 15 1/2"