Essential Pebbles, Volume 1 is the first compilation album in the Essential Pebbles series. Although subtitled Ultimate '66 garage classics!, not all of the recordings on the album were originally released in 1966.

"Let It Out (Let It All Hang Out)" is a 1967 song by the Hombres and the title track of their album of the same name. It is, according to AllMusic journalist Stewart Mason, a "deadpan southern-fried parody" of Bob Dylan's "Subterranean Homesick Blues".