TAMBOURINES The most common classification of percussion instruments divides them into 2 categories, of definite pitch and of indefinite pitch. The latter includes most of the smaller percussion instruments, like triangle, tambourine, castanets, cymbal, gong and sleigh bells. The tambourine is a small drum with a single calfskin head. In the narrow shell are openings where pairs of thin brass discs, called "jingles", are set on wires.