Nicholas Caldwell, co-founder and singer of R&B band The Whispers, died of heart failure Tuesday at the age of 71, according to the Associated Press. Willette Ballard, the California-based group's representative, confirmed that Caldwell passed away at his residence in San Francisco.

Caldwell, who penned the group's popular song "Lady," formed The Whispers in 1963 as a quintet along with twin brothers Walter and Wallace Scott, Marcus Hutson (who died in 2000) and Gordy Harmon. Harmon left the band a decade later and was replaced by Leaveil Degree, according to Rolling Stone.

The Whispers delivered their first top 10 R&B hit in 1970 with "Seems Like I Gotta Do Wrong." The group's 1979 album "The Whispers" was their first one to go platinum, and included the popular hit "And The Beat Goes On," which was sampled by Will Smith in his track "Miami," according to Entertainment Weekly. The group then topped the charts with "Rock Steady" in 1987, which was produced by Antonio "L.A." Reid and Kenneth "Babyface" Evans. Still active, The Whispers most recent gig was in Hammond, Ind., Saturday.