Classical Guitar Study - Rework and Acoustic Testing of Experimental Guitars #6, #7, #8, #9

These are handwritten research and development notes from 1978 documenting the construction, bracing patterns, and acoustic testing of several experimental guitars (numbered #6 through #9) compared against a Takamine C128 reference guitar. The notes cover modifications to bowl depth, bracing configurations, and tonal characteristics including body, treble, sustain, and clarity. Detailed diagrams of bracing patterns are included alongside measurements for a proposed new classical guitar design.