The Crystals are an American vocal group that originated in New York City. Considered one of the defining acts of the girl group era in the first half of the 1960s, their 1961–1964 chart hits – including "There's No Other ", "Uptown", "He's Sure the Boy I Love", "He's a Rebel", "Da Doo Ron Ron" and "Then He Kissed Me"– featured three different female lead singers and were all produced by Phil Spector. The latter three songs were originally ranked number 263, number 114, and number 493, respectively, on Rolling Stone magazine's list of The 500 Greatest Songs of All Time. However, two songs were omitted from the magazine's 2010 update, leaving only "He's a Rebel" at number 267. In the 2021 update, "Da Doo Ron Ron" was added back to the list at number 366.

A girl group is a music act featuring several female singers who generally harmonize together. The term "girl group" is also used in a narrower sense in the United States to denote the wave of American female pop music singing groups, many of whom were influenced by doo-wop and which flourished in the late 1950s and early 1960s between the decline of early rock and roll and start of the British Invasion. All-female bands, in which members also play instruments, are usually considered a separate phenomenon. These groups are sometimes called "girl bands" to differentiate, although this terminology is not universally followed.