9 stopper multifold bellow special heavy fitting, coupler, A440 international scale tunning harmonium. A440 pitch - set of 2 "Harmonica" reeds: 1 bass + 1 male for rich sound 3 1/2 octaves total 42 keys coupler function - helps to play two octaves of the same note at the same time and produces richer sound a440 pitch.
9 stopper multifold bellow special heavy fitting, coupler, A440 international scale tunning harmonium. A440 pitch - set of 2 "Harmonica" reeds: 1 bass + 1 male for rich sound 3 1/2 octaves total 42 keys coupler function - helps to play two octaves of the same note at the same time and produces richer sound a440 pitch.
9 stopper multifold bellow special heavy fitting, coupler, A440 international scale tunning harmonium. A440 pitch - set of 2 "Harmonica" reeds: 1 bass + 1 male for rich sound 3 1/2 octaves total 42 keys coupler function - helps to play two octaves of the same note at the same time and produces richer sound a440 pitch.