Along with Buck Owens and Merle Haggard, Simpson is credited with helping to pioneer what became known as “The Bakesfield Sound,” utilizing electric guitars with elements of Rock and Western Swing, all of which were a stark contrast to what had become a slicker, Orchestra-driven sound originating from Nashville in the late 50s.

Raised in Bakersfield and a product of the club scene there, Simpson soon became a Capital Records label mate of Owens and Haggard, penning songs with both and performing on Haggard’s “Okie From Muskogee” single. But Simpson carved out his own niche with a series of trucker-themed songs in the mid-60s, starting with “Roll Truck Roll” and “Highway Patrol” in 1966. His most notable hit was 1971’s “I’m A Truck,” which attained a top 5 chart position.