Musical bellows instrument provided with an electro-pneumatic control device operated by the bellows movement

In a musical instrument having a keyboard and bellows for causing pressure differentials during contraction and expansion and reeds responsive to said pressure differentials to produce a musical output, a control for varying the volume of said musical output, special effects means for providing alteration outputs to alter said musical output and thus provide effects such as brilliancy, fluttering and the like, and preset switch means for presetting the special effects means to be used to alter said musical output, the improvement comprising:

• a flexible membrane in communication with the interior of said bellows and responsive to said pressure differentials;
• an electronic circuit comprising gate means for gating said alteration outputs to said musical output in accordance with a control voltage supplied through said preset switch means when said preset switch means is closed;
• variable switch means connected to said flexible membrane and adapted to provide said control voltage through said preset switch means to enable and disable said gate means in accordance with the movement of said flexible membrane;
• and
• said variable switch means, present switch means, gate means, and special effect means integrated such that the special effects may be changed during playing of the instrument without the need for removal of the musician's hands from the keyboard.