Clayton is best known for her 1969 duet with Mick Jagger on the Rolling Stones song "Gimme Shelter" (though on some releases her name is misspelled as "Mary"). According to Jagger, the collaboration happened partially by chance: Jagger stated that the band thought, "it'd be great to have a woman come do the… chorus." They called Clayton "randomly" in the middle of the night, and she showed up to the studio "in curlers" and contributed her parts in a few takes, which Jagger remarked was "pretty amazing." Clayton performed her parts while pregnant, soon afterward suffering a miscarriage; some have attributed the miscarriage to the physical strain from her exertions during the recording. Clayton was actually the band's second choice for the part; The Stones had asked Bonnie Bramlett to sing on the song, but Bramlett's husband Delaney refused to let her perform with the Stones.