By the mid-1930s, she had met and been influenced by Fats Waller, and performed regularly as a singer and pianist in Chicago clubs. In 1948, Davis and Ponder moved to California, and Davis developed her recording career on Jewel Records in Hollywood with a trio including Ponder, Ralph Williams (guitar) and Lee Young (drums). Their cover of Dick Haymes" popular hit "Little White Lies" reached # 11 on the Billboard Rhythm & Blues chart, followed by a duet with Louis Jordan, "Daddy-O" in 1948, which reached #7 on the Rhythm & Blues chart that year.
Davis and Ponder also began performing together on stage, developing a musical and comedy routine as "Martha Davis & Spouse" which played on their physical characteristics (she was large, he was smaller).
The act became hugely popular, touring and having a residency at the Blue Angel in New New York They appeared together in movies including Smart Politics (with Gene Krupa), and in the mid-1950s, variety films Rhythm & Blues Revue, Rock "n" Roll Revue and Basin Street Revue.
Several of their performances were filmed by Snader Telescriptions for video jukeboxes, and they also broadcast on network television, particularly Garry Moore"s Columbia Broadcasting System show. In 1957, after a break of several years, they resumed recording for the American Broadcasting Company Paramount label, with whom they cut two LPs.
Davis died from cancer in New York in 1960, aged 42, and Ponder died ten years later, aged 53.