He was an American singer-songwriter and guitarist. He was from Farmers Branch, Texas.
He was a one-hit wonder, hitting the US charts in 1975 with the single “Judy Mae”, which peaked at #33.
Castleman was the inventor of the palm pedal, a device that allows guitar players to execute pedal steel-style string bends.
He made his original prototype in 1968, and the device is now marketed under the name Bigsby Palm Pedal.
The original patent has expired, allowing other vendors to market similar devices, but the Bigsby/Castleman version is the original.
Castleman founded the independent country music record label BNA Records which he later sold to BMG Music.