George Murphy "Pops" Foster was an American jazz musician, best known for his vigorous slap bass playing of the string bass. He also played the tuba and trumpet professionally.

Slapping and popping are ways to produce percussive sounds on a stringed instrument. They are primarily used on the double bass or bass guitar. Slapping on bass guitar involves using the edge of one's knuckle, where it is particularly bony, to quickly strike the string against the fretboard. On bass guitars, this is commonly done with the thumb, while on double bass, the edge of the hand or index finger may be used. Popping refers to pulling the string away from the fretboard and quickly releasing it so it snaps back against the fretboard. On bass guitar, the two techniques are commonly used together in alternation, though either may be used separately.