Complex sentence: During the 1960s, Shelton was a session musician working in recording studios around Hollywood, and among his more notable session work was for The Monkees, including their first self-titled album, and both recordings of the Boyce and Hart song "Valleri".
Split into simpler sentences: During the 1960s, Shelton was a session musician working in recording studios around Hollywood. Among his more notable session work was for The Monkees, including their first self-titled album, and both recordings of the Boyce and Hart song "Valleri".