Legendary folk musician Pete Seeger has passed away. The hugely influential troubadour, best known for 'If I Had a Hammer' and 'Turn, Turn,Turn,' died Monday (Jan. 27) at the age of 94.

According to multiple media reports, Seeger died of natural causes at New York Presbyterian Hospital. His grandson, Kitama Cahill-Jackson, tells the Associated Press that he was in good health until the very end of his life.

"He was chopping wood 10 days ago," he shares, adding that family members were with Seeger when he died peacefully in his sleep after a hospital stay of six days.

Seeger's influence on American roots music spanned decades, but he was also a controversial figure; his social activism made him a hero to some, and a pariah to others, especially during the height of anti-Communist sentiment in the '50s, when he was forced to testify before the House Un-American Activities Committee.

Pressed to answer whether he had performed for Communists, Seeger sharply replied, "I love my country very dearly, and I greatly resent this implication that some of the places that I have sung and some of the people that I have known, and some of my opinions, whether they are religious or philosophical, or I might be a vegetarian, make me any less of an American."

He was charged with contempt of Congress, which was later overturned on appeal. But though Seeger later renounced the Communist Party, the association dogged him for years, keeping him off mainstream television for the next decade. His return to the airwaves on an episode of the Smothers Brothers' variety program spelled the end of the Hollywood blacklist of entertainers with suspected ties to communism.

Seeger maintained both his music and his activism into his later years, though he had to rely on audiences to sing along after losing most of his singing voice. His later causes included civil rights and environmental issues, as well as opposing the war in Iraq. He also supported the Occupy movement.

"Be wary of great leaders," he told The Associated Press in 2011. "Hope that there are many, many small leaders."

Seeger leaves a legacy of using music as a tool not just for entertainment, but for change.

"There's not dozens of people now doing what I try to do, not hundreds, but literally thousands," he said in 2008. "The idea of using music to try to get the world together is now all over the place."