The soundtrack -- featuring songs by Christopher Guest, Eugene Levy, Catherine O'Hara and Harry Shearer, as well as McKean and O'Toole -- has scored Grammy nominations. It's up for best compilation soundtrack album, and its title song -- written by Guest, Levy and McKean -- is up for best song written for a movie, TV or other visual media.
"A Kiss at the End of the Rainbow" was overlooked at the Grammys, even though it represents probably the emotional high point in "A Mighty Wind." As performed by Levy and O'Hara, the number provides a rare moment of quiet reflection in an otherwise rowdy send-up of commercialized folk music in the 1960s.
"We're kind of amazed that people have responded to it so strongly," said McKean in an interview with United Press International. "The song had become a character by the end of the film, helped along by Catherine and Eugene."
Levy and O'Hara played Mitch and Mickey, a folk duo whose relationship was wrecked by Mitch's personal problems -- including substance abuse. As they sing the song during a reunion concert, they seem to reconnect.
McKean said the song provided "a rooting interest" in the movie, and still resonates at live shows during which he and others from the cast perform songs from the movie.
"We end with Mitch and Mickey," he said, "and there's not a dry eye in the house."
"It's so much fun," she said. "It's a beautiful instrument and I'm able to compose on it now."
However, O'Toole -- who spends much of her time in Vancouver, Canada, filming her role as Martha Kent on the WB's "Smallville" -- said she has her limitations. She often calls on McKean to help her work out musical ideas over the telephone.
"What I have in my head, I can never do on the instrument because I'm not good enough yet," she said. "I call him from Vancouver and sing it to him."
When she is in Los Angeles O'Toole often stands just offstage at the "Mighty Wind" concerts. She also had a hand in writing "Fare Away" and "Potato's in the Paddy Wagon," but she and McKean are focused on promoting "A Kiss at the End of the Rainbow."
McKean said the campaign that he and O'Toole are waging is being taken seriously.
"We don't have our faces laughed in just yet," he said. "We also watch the Oscars and we've seen some of the songs that have been nominated over the past 35 years, going back to 'Hush, Hush Sweet Charlotte.' They're always scraping to get five (nominees). This song, all things being equal, has a good chance of being nominated."
The songs on "A Mighty Wind" have what you might call the T Bone Burnett "seal of approval." The Grammy-winning producer has been a hot commodity in Hollywood, particularly since the success of his soundtrack for "O Brother, Where Art Thou?"
Most recently, Burnett supervised the soundtrack for the upcoming Nicole Kidman-Renée Zellweger movie "Cold Mountain." He served as executive producer for the "Mighty Wind" soundtrack, but the music was actually produced by C.J. Vanston -- who has worked in the past with Joe Cocker and Dolly Parton, and played keyboards for an earlier Guest-Levy-McKean collaboration, "This Is Spinal Tap."
McKean said that, just as "Spinal Tap" had cast a good-natured lampoon at big-hair, heavy metal music, "A Mighty Wind" wasn't aiming its satire at folk music -- just at certain practitioners of the form.
"It became very commercial, it became very contrived," he said. "Too many guitars, with bands like 'The Back Porch Majority,' and 'The Serendipity Swingers,' it became Orwellian after a while."
McKean -- still probably best known as Lenny Kosnowski from the classic TV comedy "Laverne & Shirley" -- observed that much comedy these days is grounded in cruelty. He said he and his "Mighty Wind" collaborators refuse to play that game.
"It's not what we do," he said. "There is a certain amount of ridicule involved, and damaged individuals. Having said that, I think it's basically an affectionate film."
Also, it's profitable -- although McKean admitted that the numbers involved cannot compare with the kinds of numbers that blockbuster hits routinely deliver.
"We're not going to make the kind of money that you could make with a big number after the title," he said, "but all these films are well into profit, and we're happy about that. And the people who like them really do love them. They haven't seen anybody torn apart and it's gentle."
2014: The Year in Music [PHOTOS]