Historically, the Million Dollar Quartet was an impromptu jam session among four young stars who made their mark at Sun Records. The quartet? Jerry Lee Lewis, Carl Perkins, Johnny Cash and Elvis Presley.

The musical “Million Dollar Quartet,” now playing at Old Log Theater, uses this event to spin a story about Sun Records founder Sam Phillips and his influence on early rock ’n’ roll. It also serves as an onstage jukebox.

When the young performers of the production cut loose on two dozen rocking classics like “Blue Suede Shoes,” “I Walk the Line” and “Great Balls of Fire,” the show is pure joy. But when it comes to the plot, the show comes to a grinding halt.

The story of Phillips and Sun Records is far too complex for the framing device of a musical. We want to hear classic tunes, not watch a hamfisted drama about Cash’s new contract.

The young actors ooze charisma, from Frank Joseph Moran’s slick and soulful Elvis to Eric Sargent’s stoic Cash. Eric Morris steals the show as Lewis. His character is constantly in motion, as if the music’s spirit cannot be contained in his lean body. And while Elvis had a friend present at the session, I doubt she performed firebrand versions of “Fever” and “I Hear You Knocking” the way Mollie Fischer does at the Old Log. 

Ed Huyck is a Twin Cities theater critic.