Michiganders Greensky Bluegrass are full of contradictions on their new album Shouted, Written Down & Quoted and the new song "Past My Prime" is no exception.

The track pulls from the past to make something new as mandolin player Paul Hoffman reminisces about his life's ups and downs, bringing bluegrass into a modern context with a swinging rock and roll swagger. And, as Hoffman tells Billboard, the song's creation similarly followed suit.

Remembering Ralph Stanley: The Bluegrass Legend on Billboard Charts

As the band entered the studio to record Shouted, Written Down & Quoted, armed with a load of new material to work on, Hoffman says he was moved to bring up an old song he'd written some time ago. He started rearranging it and the band joined in.

"The enthusiasm for the whole project began spilling into the unknown musical creature we were making," he says. "Frankly, I think we're all pretty stoked with the little rock and roll monster that was born from a song out of the shadows."

Steve Martin Celebrates Bluegrass Broadway Musical 'Bright Star' With Banjo Performance

Of "Past My Prime," Hoffman says it "not serious" and "not that personal," that he wrote it "in jest" and "sorta stream of conscious."

"Sometimes I can evoke more emotion with the lyrics when it's more of an exercise than personal catharsis," he says. It just took him moving on to finally finish it.

Shouted, Written Down & Quoted will be out Sept. 23 on the band's own Big Blue Zoo Records label. Listen to "Past My Prime" below, premiering exclusively with Billboard.