Lou Reed, the punk poet of rock ‘n’ roll who profoundly influenced generations of musicians as leader of the Velvet Underground and remained a vital solo performer for decades, died Sunday at 71.

Mr. Reed died in New York State of an ailment related to his recent liver transplant, according to his literary agent, Andrew Wylie, who added that Mr. Reed had been in frail health for months. Reed shared a home with his wife and fellow musician, Laurie Anderson, whom he married in 2008.

Mr. Reed never approached the commercial success of such superstars as the Beatles and Bob Dylan, but no songwriter to emerge after Mr. Dylan so radically expanded the territory of rock lyrics. And no band did more than the Velvet Underground to open rock music to the avant garde to experimental theatre, art, literature and film, to William Burroughs and Kurt Weill, to John Cage and Andy Warhol, Reed’s early patron.

Indie rock essentially began in the 1960s with Mr. Reed and the Velvets. Likewise, the punk, New Wave and alternative rock movements of the 1970s, ‘80s and ‘90s were all indebted to Mr. Reed, whose songs were covered by R.E.M., Nirvana, Patti Smith and countless others. “The first Velvet Underground record sold 30,000 copies in the first five years,” Brian Eno, who produced albums by Roxy Music and Talking Heads, among others, once said. “I think everyone who bought one of those 30,000 copies started a band!”

Mr. Reed’s trademarks were a monotone of surprising emotional range and power; slashing, grinding guitar; and lyrics that were complex yet conversational, designed to make you feel as if Mr. Reed were seated next to you.

More In: World | International