091 / Diamond Girl by Seals and Crofts, 1973
Seals and Crofts is like a whole big thing of 6 degrees of separation.
Jim Seals and Darrell Crofts were both part of a local bad in Texas. They moved to Los Angeles to join The Champs. Along fellow bandmate was Glen Campbell ("Rhinestone Cowboy" and "Witchita Lineman"), they formed a new band called Glen Campbell and the GCs.
After that band broke up, Seals and Crofts joined The Dawnbreakers, which also proved to be unsuccessful. It was then that they decided to play as a duo with Seals on guitar, saxophone, and violin and Crofts on guitar and mandolin.
Another fun fact: Jim Seals is the brother of "England" Dan of England Dan and John Ford Coley (famous for "I'd Really Love To See You Tonight").