A founding member of one of the first underground rock groups, the Fugs, has died.
His friend and bandmate Ed Sanders said Kupferberg had suffered strokes in the past year.
Although never a commercial success, the Fugs were a regular attraction at anti-war protests in the 1960s. Kupferberg once joked they were "the U.S.O. of the left."
His contributions were recognized in January when Lou Reed, Sonic Youth and others appeared at a benefit concert in Brooklyn to help pay for some of his medical expenses.
Sanders says Kupferberg will be remembered as a unique American songwriter.