In the early 1980s, he was a member of the band Revolver, headlined by Tim McCrary, which played extensively in Texas.
After a stint living in California, he returned to Texas, where, in 1987, he met then-struggling country singer Clint Black.
Nicholas has been twice nominated for the CMA Song of the Year, in 1989 for "A Better Man" and in 1990 for "Killin' Time," both co-written with (and recorded by) Clint Black.
One of his collaborations with Black, The Hard Way, was included in the musical Urban Cowboy, which was nominated for a 2003 Tony Award for Best Original Score.
He also played guitar on the Asleep at the Wheel album Ride with Bob, and wrote a novel, Hands Treasure, which has been optioned by a motion picture company.