Billie Rae Calvin was an American soul singer-songwriter, born on May 12, 1949, in Los Angeles, California. She initially gained attention as a member of the Los Angeles-based girl group The Delicates, alongside Brenda Joyce Evans. After The Delicates disbanded in 1970, Calvin and Evans became background vocalists for Motown artists, contributing to hits like Diana Ross's "Ain't No Mountain High Enough" and the Four Tops' "Still Water (Love)."

In 1970, Motown producer Norman Whitfield assembled The Undisputed Truth, a psychedelic soul group, with Calvin, Evans, and Joe Harris. The group was known for their unique sound and striking visual style, characterized by large Afros and white makeup. They achieved their biggest success with the 1971 hit "Smiling Faces Sometimes," which reached number three on the Billboard Hot 100.

Calvin was also a talented songwriter, known for penning the classic ballad "Wishing On A Star," famously performed by Rose Royce. Despite the success of The Undisputed Truth, Calvin left the group in the early 1970s. She passed away on June 23, 2007, in Murrieta, California, due to heart disease.