An innovative guitarist best known for his collaborations with Tim Buckley. His style has been described as unlike any other in the rock or folk-rock genres, often involving extended improvisation around jazz-like harmonic development.
Leaving the University of Colorado in his sophomore year, he moved to California, re-entered school, got married and graduated from San Francisco State College. While still a student, he picked up a second-hand guitar and began strumming and singing folk songs.
His brief attendance in graduate school at UC Berkeley did nothing to expand his mind or his talents and he quickly dropped out. He and his wife moved East, where he taught high school English in New Jersey for a year.
After his marriage dissolved, Underwood ran away to Mexico with a vivacious, dark-skinned dancer named Jennifer Stace and travelled on to San Francisco, where he wrote his own folk songs and sang them in North Beach clubs and coffee houses.
In the spring of 1966 in Greenwich Village, he met a 19-year-old singer/songwriter named Tim Buckley. They teamed up and throughout the late 1960s and early 1970s Underwood played lead guitar on 7 of the 9 albums Buckley recorded while alive, including Goodbye and Hello, Happy Sad and Starsailor. He toured America and Europe with Buckley for 7 years and remained one of the singer's best friends until Buckley's untimely death in 1975 from an accidental overdose of alcohol and heroin. An aspiring jazz guitarist when he first met Buckley, Underwood easily followed his musical partner from the quiet, hypnotic folk-jazz style into the noisy and abrasive world of a large avant-garde rock band featuring the silver-haired, horn-playing brothers Buzz and Bunk Gardner.
The guitarist was eventually edged out of the Buckley scene when that artist began developing yet another style consisting of loud, free-form funk and was replaced by Joe Falsia. The contribution he had made to the world of Buckley is generally considered major, with many reviewers ready to give him equal creative credit.