The left of accordion a keyboard keys - buttons has seven rows.

摘要

The accordion has a left keyboard comprising seven rows and composed of two juxtaposed sub-keyboards. One sub-keyboard has four rows of buttons vertical and parallel to disposition of notes of a right keyboard. The other sub-keyboard has three rows with notes such that notes of adjacent rows are equal to a musical interval of k tones, where k varies from zero to five octave. Each group of any four consecutive notes in one row forms an adjacent series with a group of any four consecutive notes of another row.