TetraCurrent is a grooving intermediate marimba quartet featuring syncopated accompanimental tone clusters and memorable melodies. Marimba 1 (4-octave) Marimba 2 (4-octave) Marimba 3 (4-octave) Marimba 4 (5-octave) * Players 1 and 4 may share one 5-octave instrument.