Hearts of Stone was an American R&B vocal group, best known for their work with Motown Records in the mid-1970s. The group's distinctive sound was marked by soulful harmonies and rich orchestration, representative of the Motown sound of the era. They are most recognized for their cover of the Impressions' "It's a Man's Man's Man's World," which has been influential in the R&B genre. Despite their relatively short career, the Hearts of Stone left a lasting impact on the Motown sound and the broader landscape of American rhythm and blues.