Andrus was raised in New England and studied at the Manhattan School of Music. In the late 1940s he formed his own ensemble in Springfield, Massachusetts which included Sal Salvador and Phil Woods. He played with Charlie Barnet in 1953, then with Claude Thornhill through the middle of the decade. While with Thornhill he met Terry Gibbs, and the two frequently played and recorded together in subsequent years. As a freelance musician in New York, Andrus worked with Don Stratton, Bernard Peiffer, and Jim Chapin; he also recorded extensively with Woody Herman.
With Woody Herman
- Woody Herman–1963 (Philips, 1963)