Jam block

A jam block is a percussion instrument which is a modern, hard plastic version of the wood block. It is sometimes referred to as a "clave block", "gok block", "tempo block" or in marching band terms, "gock block". Jam blocks are popularly used for their sturdiness and durability compared to the traditional wood block, as well as in cowbell-like roles.

Jam block

Percussion instrument
Classification	Percussion
Hornbostel–Sachs classification	111.2 (Percussion idiophones)
Related instruments
wood block, temple blocks, muyu, slit drum
Builders
LP, Pearl, Meinl, Toca

Jam blocks are usually attached to timbales and drum kits, but can also be used as standalone orchestral instruments. These blocks are often used in salsa and other Latin American styles, although some modern drummers have made use of them in rock songs. Jam blocks are often used in the marching percussion idiom as well.

There are several manufacturers of jam blocks, including LP, Pearl, Meinl, and Toca. Manufacturers typically color-code their jam blocks by size/pitch. Variants include sambango bells, granite blocks, "stealth" and "blast" blocks, and hybrids incorporating elements of a güiro or tambourine.