Abstract: The complete drum comprises two, axially-separable, generally cylindrical sections, which are open, inwardly, toward each other, each of these two sections having but one playing head, so that the two heads are disposed respectively at the outer ends of the cylindrical assembly. When the open ends of these two basic sections are axially spaced-apart to provide an annular gap between them, the space within said sections communicates with the ambient air, through said gap, substantially uniformly around the periphery of the drum. This construction, with gap, is intended to provide any desired increase in volume, and a great variety of tonal modifications.Means are provided for adjustably varying the size of the gap, or for closing it altogether; whereby the volume, pitch, dynamics, and tonal characteristics of the drum may be varied. This may be done by using adjustable holding means, and/or by using perforate or imperforate cylindrical filler pieces.

Abstract: A mallet for playing upon musical instruments comprises a hard shaft with a handle end and a head end, and having a head retainer at the latter end, and additional retaining means inboard thereof, there being a replaceable playing head which is centrally apertured to pass lengthwise onto the shaft, from the handle end to the head end, where it is held against flying off, by means of said retainer, and is held against slipping back over the shaft, by means of said retaining means; the head having at least the central zone, around said aperture, formed to be resiliently yieldable, whereby the head may be forced over or onto the said retaining means.