• <EXTENDING>
  In manipulating the bellows, the first movement is to draw outward (extending) in a fanlike shape, allowing the upper part to open almost by its own weight, while guiding it as near straight as possible with the left wrist against the strop. The forearm should not brace against the inner side of the bassboard panel but may rest lightly, though firmly, upon it.
• <DEPRESSING>
  In depressing bellows (inward) the main pressure is applied by the left hand to the upper part, allowing the lower section to open. As the upper part closes the lower section, having opened, is now ready to be depressed, as the upper part is again drawn outward, resulting in a continued flow of air. If these movements are smoothly executed, there should be hardly any interruption in sound.
  The manipulation of the bellows should become an involuntary habit in time, syncronizing with the fingers without any conscious effort.
• <CONTROL>
  After bellows control is fairly well established, the student will realize that no fixed rule can be applied to its manipulation. The player must use his or her discretion, adjusting the changes in conformity with the phrases of the composition; as a singer breathes (in musical phrases) so should the bellows be treated. Avoid changing in the middle of a legato passage or run.

「CHARLES MAGNANTE'S ACCORDION METHOD」より抜粋