FIELD: reed musical instruments. SUBSTANCE: device has left and right halves of assembly with decks, keyboards, fingerboard with keyboard and input chambers which have sounding compartments with acoustic valves for melody, bass and treble. Bass input chamber contains acoustic lathes of smaller octave which are arranged in pairs in perpendicular to longitudinal axis of input bass chamber between parallel sounding compartments with acoustic lathes for counter octave and greater octave. Projection of locations of sounding compartments with acoustic lathes for counter, greater and smaller octaves of same name are L-shaped. Valves of input bass chamber which covers input holes of sounding compartments with acoustic lathes for counter, greater and smaller of same name are L-shaped. EFFECT: increased output of treble region without increase in size of device. 2 cl, 4 dwg
