Abstract: A guitar or similar musical instrument with a resonator cone insert has been improved in several respects. My improvements include the development of a structural support ring made of graphite with circumferentially aligned strengthening fibers integrated within the circumference of the support structure, a sealing ring for sealing the cone cover in the structural support ring, the sealing ring being tubular in cross section and compressed to a figure-8 cross section to create additional pressure for holding the cover plate in place securely and eliminating "rattling" of the cover plate to distract from the sound of the instrument. Another feature of the design of the present invention is the provision of a interlocking connection between the structural support ring and the resonator support ring which allows one to change the size, shape and configuration of the resonator support ring to create different sounds.