McManhan 77, died at his home in Van Nuys of neuropathy and an unrelated blood disease, his stepson Steve Land said.
McMahan played trumpet on The Lawrence Welk Show" from 1967 to 1982. He also played with Les Brown's Band of Renown on The Steve Allen Show" in the 1950s and '60s and toured with Brown's band when it accompanied comedian Bob Hope on USO tours entertaining the military overseas.
Clinton O. McMahan was born on Aug. 23, 1930, in Texas. His mother, who had learned to play trumpet in an orphanage where she grew up, taught him to play the instrument.
When Mickey was young, she was trying to get him to take piano lessons, but once he got hold of her trumpet he never gave it up," Land said.
The family moved to Arizona when McMahan was a child. He moved to California after high school and later served in the Army.
A tribute to McMahan will be held Sunday from 2 to 5 p.m. at Casey's Tavern, 22029 Sherman Way, Canoga Park.