Two minutes and ten seconds of pop perfection:
They had a complicated history, the Crystals - things were always complicated when Phil Spector was involved - but the lead singer here would seem to be Dolores "La La" Brooks, with Francis Collins and DeeDee Kennibrew. From 1963.
The "Let's Dance the Screw" saga:
The next single credited to The Crystals is one of the rarest—and also possibly the strangest—in rock music history. Reports vary as to the actual motivation behind the recording, but most agree that Phil Spector was looking for a way to annoy former business partner Lester Sill. What he came up with was a nearly six-minute song called "Let's Dance The Screw - Part I", which would have been unplayable on 1963 radio. The record featured simple instrumentation (very much unlike Spector's famous Wall of Sound production style), repetitive lyrics, and Spector himself intoning the lyric "Dance The Screw" numerous times in a deadpan monotone. (The B-side, Part II, was more of the same but played much more slowly.) The Crystals sang the song's repetitive verses, though it is unclear if these singers were the 'original' Crystals or The Blossoms. Incidentally, some accounts mention that Spector's lawyer is actually the man intoning "Dance The Screw."
The recording was never released commercially as a single, and only a few copies are known to exist (all marked 'DJ copy - not for sale'). The record was apparently only created to be a bizarre sort of joke at Sill's expense, who was soon to leave the Philles label, as a single copy was specially delivered to him in early 1963.
For your listening pleasure here.