Tambour (also called tambor, tamboro or tambora, written in music as tamb.
The player uses a flat part of the hand, usually the side of the outstretched right thumb, or also the edge of the palm below the little finger, and sounds the strings by striking them rapidly just inside the bridge of the guitar.
If performed incorrectly, the effect is similar to a right-hand apagado, or dampening of the strings.
An example of tambour in popular music occurs at the beginning of the second verse of Your Time Is Gonna Come by Led Zeppelin.
One of the most remarkable modern compositions for the guitar, Sonata op.47, by Argentine composer Alberto Ginastera, was inspired by the folk music of Indians and Argentinean Gauchos and uses a lot of effects typical of the guitar, such as tamboro.