Although it looks very similar to the gong, it is typically thinner with a smaller rim and has no nipple or protrusion in the center. The tam-tam tends to be either flat or saucer-shaped. The shape and construction produce a great difference in sound. The gong has a definite pitch center with a fundamental note producing rich overtones, and the tam-tam should have no discernable pitch or fundamental note, simply a crash of dissonant frequencies.