It’s been called the best power pop album of all time. Matthew Sweet’s “Girlfriend” is a beautiful paradox – a break-up album that is lyrically devastating but sonically optimistic, and it features a killer roster of musicians, including Lloyd Cole, Television’s Richard Lloyd and both members of the Indigo Girls. The 1991 anime-style video made Sweet an MTV star, back when music videos were still the reason to watch MTV.Actors Theatre of Louisville opens a musical based on Sweet’s landmark heartbreaker this week. “Girlfriend” opens Thursday and runs through February 17 in the Pamela Brown Auditorium.Directed by artistic director Les Waters, playwright Todd Almond’s “Girlfriend” uses the album’s songs to tell the story of a romance between two young men on the brink of adulthood in a small Midwestern town—much like the one Almond grew up in, listening to Sweet’s album at 15 and honestly believing the world would end if his crush didn’t call him back.“There’s such joy and such humanity in those songs,” says Almond. “They’re really sad—really, really sad—when you listen to the lyrics, but there is a buoyancy to the whole thing that’s addictive.”He’s channeled those intense adolescent feelings into a musical about a romantic relationship between two young men that uses Sweet’s album as its soundtrack—with a live, all-women band led by Julie Wolf—and as a shared language between the two boys. It’s a musical—the actors sing live on stage—but the music functions differently in “Girlfriend.” Almond says the music is “a little sneaky in its approach.”“The music doesn’t arrive in the show because the boys are so happy they need to express it in song, or so sad they need to express it in song,” says Almond. “The music is actually a commodity between them. The music exists in their world. They make mix tapes for each other and they like these songs, and the songs become substitutes for the things they can’t say out loud.”Will (“the quiet gay kid in school who’s not particularly ambitious”) gets the surprise of his young life when popular, athletic Mike turns to him in class and says those magic words: “I made you a tape.” (Mix tapes, those analog artifacts from the brief time between vinyl and CD-Rs, in which so much could be written between the track listing lines!) But Mike has a girlfriend, so the gesture doesn’t exactly mean what Will hopes. The play then follows the two through the summer as their relationship develops.“I remember making tapes for people and putting certain songs on there and secretly hoping they would pick up on what I was trying to say, but if they were offended by that I could say it’s just a song, it doesn’t mean anything,” says Almond. “And that’s kind of what’s happening in this musical. The boys are like, I’m singing this song, what do you think about that?” Waters directed the 2010 world premiere of “Girlfriend” at Berkeley Repertory Theatre, where he served as associate artistic director before taking the reins at Actors Theatre last year. Reprising their roles in this production are Ryder Bach (Will) and Wolf, the bandleader and a seasoned touring and studio musician (Ani DiFranco, the Indigo Girls, Erin McKeown). Curt Hansen (Mike) joined the cast for a special concert production at Joe’s Pub in New York last year. Louisville drummer Jyn Yates, bassist Sara Lee (Gang of Four, Robyn Hitchcock, The B-52s) and Cincinnati-based guitarist Kelley Richey round out the band.Almond says he knows people might be nervous about a writer imposing a different narrative on top of an album they love (Sweet wrote “Girlfriend” about his divorce from his first wife). But he says the play is more about one writer’s—one fan’s—relationship with the album, which is rooted in the experience of falling in love with the music as a teenager.“As teenagers, if that boy doesn’t call me back it is the end of the world, I don’t know how I’m going to survive. Somehow the music we listen to attaches to those giant emotions and they stay with us forever,” says Almond. “I bet Proust has something interesting to say about that.”Watch the video for "Girlfriend"http://www.youtube.com/watch?v=JcFiWWzdyJg