Singer-songwriter Don McLean, right, is interviewed by Bill Cohen at a screening of a documentary about his life at the Motion Picture Associatino of America (Joy Asico for MPAA)

Boomer politicians are always eager to show off their rock-and-roll bona fides — their iPods filled with Rolling Stones, their Springsteen ticket stubs. But the Maine delegation has coalesced behind a mellower sound: Don McLean.

At an MPAA screening of a new documentary about him Tuesday, Sen. Susan Collins (R) explained how her singer-songwriter constituent (he lives in coastal Camden) provided the soundtrack to her recent wedding.

“At our rehearsal dinner, my sister, who is a great musician, asked me what music we wanted. And I said, of course, we have to do ‘American Pie’. . . I was amazed! My nieces and nephews all knew the words! Talk about having a lasting impact and becoming a part of American culture.”

Another fan from the Pine Tree State was also there: former senator and defense secretary Bill Cohen, who played moderator and tried, as have many before him, to get the balladeer to explain his cryptic eight minute, 33 second epic. “American Pie,” McLean said, came from his desire to craft a “big song” that would encompass all the tumult of the 1960s. It ended up, of course, being the massive, generation-crossing singalong smash that virtually eclipsed the rest of an otherwise solid career (including hits like “Vincent” and “And I Love You So”).

Record exec “Clive Davis wanted to give me all these hit songs, but I didn’t believe in them,” McLean said. “I didn’t regret not prostituting myself, though now and again, I guess I did.”

Don McLean in 1972 (AP file photo)

Really? The documentary, “Don McLean: American Troubadour,” which has aired on PBS, depicts his family in Maine enjoying a more-than-comfortable rustic lifestyle. And legend has it a reporter once asked him what “American Pie” means, and he responded: “That I never have to work again.” True?

“Yes, it’s true,” he laughed. After some unpleasant legal battles in the ’80s, “I own all the songs, all the records.”

Amazing thing about Don McLean: The documentary reveals that his singing voice (which “could cut through steel,” as Brian Wilson puts it) is as clean and pure at 67 as it was at 26.

Healthy living? Not especially, McLean said. He drinks now and then; he used to smoke. So how’s he do it? “Bed rest,” he told us. “And no yelling.”

(Video: Don McLean singing “American Pie,” 1972)

Also in The Reliable Source:

Hey, isn’t that. . . ?: John and Teresa Kerry

Chris Brown brings Rihanna to court date

Ashley Judd responds to American Crossroad ad

Celebvocate: Chris Rock, Tony Bennett, Amanda Peet on gun violence

‘Knife Fight,’ new indie film by political strategist Chris Lehane, starring Rob Lowe, debuts on cable

‘Homeland’s’ Abu Nazir: Actor Navid Negahban on playing terrorists, getting recognized in airports