PHILADELPHIA (CBS) –– The Pew Center for the Arts & Heritage is helping tell the story of how gospel music helped influence the sound of rock as well as how the Grammy award-winning group Dixie Hummingbirds played a role in that evolution.

Rev. Joseph Williams, now the last living member of The Dixie Hummingbirds, discussed the Philadelphia premiere of “How They Got Over.”

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Williams detailed his time as a Dixie Hummingbird and how black gospel music shaped rock music and simultaneously helped healed a nation during the tumultuous civil rights era.

“Gospel music was the fuel that kept the buses running,” he said. “Gave hope to hopeless people.”

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Williams recalled how often gospel music faced down hate and lifted up the freedom movement.

“They locked up the freedom riders up in jail and they took their mattresses,” he said. “They made up a song. You can take my mattress and the jailers said stop singing that song!”

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Williams was inspired to share his experiences and is presently working with an author to complete a book detailing his life as a Dixie Hummingbird.