Heavy metal gallop

A gallop is a beat or rhythm typically used in traditional heavy metal songs. It is created by playing an eighth note followed by two sixteenth notes, usually on rhythm guitar, drums, or bass.
One technique on guitar involves strumming palm muted power chords in an up-and-down motion with a pick, thereby creating an ostinato.
Variations include the triplet gallop and the reverse gallop.
On drums, the technique often uses a double kick pedal. A typical drum gallop is formed around this skeleton:
H- x---x---x---x---|
S- ----o-------o---|
B- o-ooo-ooo-ooo-oo|

Examples of early or "proto" gallops

Several early examples are variations on the pattern that do not strictly use the "eighth note followed by two sixteenth notes", but nonetheless have been identified as gallops.