Variable Pitch Percussion Instruments

A variable pitch musical drum comprising at least one drum head the pitch of which can be varied while the drum is being played by varying the volume of air inside the drum, by varying the rate of air flow into or out of the drum, or by a combination of these two principles.  See US Patent US6198033B1 for more information.

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Multi-Annular Musical Drum

A multi-annular musical drum instrument formed from a plurality of axially aligned permanently connected rings.  Each ring formed of a multi-annular ring of laminated plywood, a solid wood or other desirable material.   The simplified construction provides a drum having a natural sound without rattling noises or a tin sound elsewhere caused by moving parts and extraneous brackets.  See US Patent US4993304A for more information.