Mary Travers of the "hugely popular" 1960s folk trio Peter, Pauland Mary died Wednesday at the age of 72 after a long battle with leukemia, said the Associated Press. The group "mingled their music with liberal politics, both onstage and off," and their version of "If I Had a Hammer" (watch a performance) became "an anthem for racial equality." They were also "early champions of Bob Dylan" and "vehement in their opposition to the Vietnam War."

Travers rose from the coffeehouse folk scene of Greenwich Village, said William Grimes in The New York Times, and she looked the part with "her straight blond hair and willowy figure." Her "powerful" voice "blended seamlessly" with those of her bearded bandmates, Peter Yarrow and Paul Stookey, "to create a rich three-part harmony that propelled the group to the top of the pop charts" with songs like "Lemon Tree" and "Puff the Magic Dragon" (watch a performance).

Even after Peter, Paul and Mary broke up in the early 1970s, said BBC News, Travers "kept up her activism," performing as a solo artist before the trio eventually reunited for benefits and other concerts. She remained active up until the middle of this year, despite her struggles with leukemia and even after undergoing a bone marrow transplant. She will be missed.