Compact teaching aid for notation for percussion instruments has six marked discs in a folder with selected rhythm viewed via windows

摘要

A compact teaching aid for the notation for percussion instrument systems has six discs, similar size to CD-ROMs, mounted in a folder to unfold with three upper discs and three lower discs, in a recess mounting. One disc of each pair is transparent and one is white. Both discs are printed with 2/4 rhythms. The user turns a pair of discs to align the 2/4 rhythm parts to form a selected 4/4 rhythm. The folder folds into a compact wallet of similar size to a CD-ROM wallet.