An accordion comprising: a right hand play side; a left hand play side; a bellow provided between the right hand play side and the left hand play side; four rows of buttons provided on the left hand play side; and two rows of buttons provided adjacent to the bellow side of the four rows of buttons or opposite bellow side of the four rows of buttons, wherein the four rows of buttons include: a first column of buttons to which first continuous four pitches that continuously follow a chromatic scale increasing in pitch from right hand side to left hand side are assigned; a second column of buttons, provided adjacent to the first column, to which second continuous four pitches that continuously follow a chromatic scale increasing in pitch from right hand side to left hand side are assigned; the second continuous four pitches being adjacent in a chromatic scale to the first continuous four pitches; and a third column of buttons, provided adjacent to the second column, to which third continuous four pitches that continuously follow a chromatic scale increasing in pitch from right hand side to left hand side are assigned; the third continuous four pitches being adjacent in a chromatic scale to the second continuous four pitches; and the pitches assigned to the buttons of the three columns increase from top play side to bottom play side direction of the accordion; the two rows of buttons include: a first column of buttons, provided adjacent to the first column of the four rows of buttons, to which first continuous two pitches are assigned, the first continuous two pitches being continuous from or to the first continuous four pitches; a second column of buttons, provided adjacent to the second column of the four rows of buttons, to which second continuous two pitches are assigned, the second continuous two pitches being continuous from or to the second continuous four pitches; and a third column of buttons, provided adjacent to the third column of the four rows of buttons, to which third continuous two pitches are assigned, the third continuous two pitches being continuous from or to the third continuous four pitches. a right hand play side; a left hand play side; a bellow provided between the right hand play side and the left hand play side; four rows of buttons provided on the left hand play side; and two rows of buttons provided adjacent to the bellow side of the four rows of buttons or opposite bellow side of the four rows of buttons, a first column of buttons to which first continuous four pitches that continuously follow a chromatic scale increasing in pitch from right hand side to left hand side are assigned; a second column of buttons, provided adjacent to the first column, to which second continuous four pitches that continuously follow a chromatic scale increasing in pitch from right hand side to left hand side are assigned; the second continuous four pitches being adjacent in a chromatic scale to the first continuous four pitches; and a third column of buttons, provided adjacent to the second column, to which third continuous four pitches that continuously follow a chromatic scale increasing in pitch from right hand side to left hand side are assigned; the third continuous four pitches being adjacent in a chromatic scale to the second continuous four pitches; and the pitches assigned to the buttons of the three columns increase from top play side to bottom play side direction of the accordion; a first column of buttons, provided adjacent to the first column of the four rows of buttons, to which first continuous two pitches are assigned, the first continuous two pitches being continuous from or to the first continuous four pitches; a second column of buttons, provided adjacent to the second column of the four rows of buttons, to which second continuous two pitches are assigned, the second continuous two pitches being continuous from or to the second continuous four pitches; and a third column of buttons, provided adjacent to the third column of the four rows of buttons, to which third continuous two pitches are assigned, the third continuous two pitches being continuous from or to the third continuous four pitches.