Douglas "Clay" Cook (born April 20, 1978) is a songwriter, producer and musician who co-wrote several songs with Grammy-winner John Mayer including "No Such Thing", "Comfortable", and "Neon". Cook and Mayer's songwriting partnership was predominantly through Mayer's early career, as the songs he wrote with Mayer (with the exception of live releases) only appear on Mayer's first two releases, Inside Wants Out and Room for Squares. Cook and Mayer formed the band Lo-Fi Masters prior to Mayer recording Inside Wants Out. Cook is currently in the Zac Brown Band and was formerly in the Marshall Tucker Band and Y-O-U.