The duo signed with Stax Records and became known as Delaney & Bonnie. They soon toured Europe with the British rock guitarist Eric Clapton. With frequent drop-in performances by other noted musicians like Duane Allman, George Harrison, and Dave Mason, the group became known as Delaney & Bonnie & Friends. Despite this all-star assistance, only two songs by Delaney and Bonnie reached the charts, their best-known "Never Ending Song of Love" and a cover of Mason's "Only You Know and I Know". Delaney and Bonnie co-wrote, with Leon Russell, "Superstar," popularized by the Carpenters, and the classic "Let It Rain", which is included on Clapton's eponymous first album.