Outsider Whose Dark, Lyrical Vision Helped Shape Rock ’n’ Roll

Lou Reed, the singer, songwriter and guitarist whose work with the Velvet Underground in the 1960s had a major influence on generations of rock musicians, and who remained a powerful if polarizing force for the rest of his life, died on Sunday at his home in Amagansett, N.Y., on Long Island. He was 71.

The cause was liver disease, said Dr. Charles Miller of the Cleveland Clinic in Ohio, where Mr. Reed had liver transplant surgery this year and was being treated again until a few days ago.

Mr. Reed brought dark themes and a mercurial, sometimes aggressive disposition to rock music. “I’ve always believed that there’s an amazing number of things you can do through a rock ‘n’ roll song,” he once told the journalist Kristine McKenna, “and that you can do serious writing in a rock song if you can somehow do it without losing the beat. The things I’ve written about wouldn’t be considered a big deal if they appeared in a book or movie.”

He played the sport of alienating listeners, defending the right to contradict himself in hostile interviews, to contradict his transgressive image by idealizing sweet or old-fashioned values in word or sound, or to present intuition as blunt logic. But his early work assured him a permanent audience.

The Velvet Underground, which was originally sponsored by Andy Warhol and showcased the songwriting of John Cale as well as Mr. Reed, wrought gradual but profound impact on the high-I.Q., low-virtuosity stratum of punk, alternative and underground rock around the world. Joy Division, Talking Heads, Patti Smith, R.E.M., the Strokes and numerous others were descendants. The composer Brian Eno, in an often-quoted interview from 1982, suggested that if the group’s first album, “The Velvet Underground & Nico,” sold only 30,000 copies during its first five years — a figure probably lower than the reality — “everyone who bought one of those 30,000 copies started a band.”

Many of the group’s themes — among them love, sexual deviance, alienation, addiction, joy and spiritual transfiguration — stayed in Mr. Reed’s work through his long run of solo recordings. Among the most noteworthy of those records were “Transformer” (1972), “Berlin” (1973) and “New York” (1989). The most notorious, without question, was “Metal Machine Music” (1975).

Beloved of Mr. Reed and not too many others, “Metal Machine Music” was four sides of electric-guitar feedback strobing between two amplifiers, with Mr. Reed altering the speed of the tape recorder; no singing, no drums, no stated key. At the time it was mostly understood, if at all, as a riddle about artistic intent. Was it his truest self? Was it a joke? Or was there no difference?

Mr. Reed wrote in the liner notes that “no one I know has listened to it all the way through, including myself,” but he also defended it as the next step after La Monte Young’s early minimalism. “There’s infinite ways of listening to it,” he told the critic Lester Bangs in 1976.

Not too long after his first recordings, made at 16 with a doo-wop band in Freeport, N.Y., Mr. Reed started singing outside of the song’s melody, as if he were giving a speech with a fluctuating drone in a New York accent. That sound, heard with the Velvet Underground on songs like “Heroin” and “Sweet Jane” and in his post-Velvet songs “Walk on the Wild Side,” “Street Hassle” and others, became one of the most familiar frequencies in rock. He played lead guitar the same way, straining against his limitations.

Mr. Reed confidently made artistic decisions that other musicians would not have even considered. He was an aesthetic primitivist with high-end audio obsessions. He was an English major who understood his work as a form of literature, though he distrusted overly poetic pop lyrics, and though distorted electric guitars and drums sometimes drowned out his words.