Don't think of "Million Dollar Quartet" as a musical. Think of it as a stage documentary about what happened on Dec. 4, 1956, when big talent, big egos and old friends came together at Sun Studio in Memphis.

The characters are familiar, no matter how limited your understanding of Sun's history. There's the hitmaker at a career crossroads (Sam Phillips), the unrecognized genius (Carl Perkins), the new kid (Jerry Lee Lewis), the man who's moving on (Johnny Cash) and the hometown boy that became a big star (Elvis Presley).

Like "Jersey Boys", "Quartet" functions almost more as a concert than a musical. The songs are straightforward versions of Sun's big hits, and I appreciated that the cast members (who play their own instruments on stage) have clearly taken care to be as faithful to that original recording as possible.

It almost goes without saying that Cody Slaughter's Elvis is authentic - he won the 2011 Ultimate Elvis Tribute Artist contest. Derek Keeling is wonderful as Johnny Cash - he's able to hit the low low notes, and he channels Cash's artistry and inner demons well.

While everyone in the show was excellent, Martin Kaye's frenetic, spastic, borderline-manic Jerry Lee Lewis completely stole the performance. Every time the show got a little weighty (and know that even the tiniest bit of heaviness seems extra heavy in such a light-hearted show), Kaye was there to jump on his piano, make a joke or fidget hilariously in a corner.

It seemed like being in Memphis gave the cast a little bit of extra enegry. It was almost like they were trying hard to make a good impression on those of us who live here (for the record, they did).  "Quartet" is fun, unpretentious and just a little irreverent, just like the city itself.

The touring Broadway production of "Million Dollar Quartet" is at the Orpheum Theatre through Feb. 19. The show runs about one hour and 40 minutes and there's no intermission. Pro tip: don't leave after the first curtain call - there's an encore of sorts tacked onto the end of the show.  Tickets are still available.