See Miranda Lambert, Ashley Monroe Surprise Fans With Live 'Heart Like Mine'

Pistol Annies members team up in Knoxville, Tennessee, during a stop on Lambert's Livin' Like Hippies Tour

Miranda Lambert welcomed Ashley Monroe to the stage in Knoxville, Tennessee, for a duet on "Heart Like Mine."

The long-rumored Pistol Annies project may be no nearer completion, but two of the trio's members did reunite onstage Thursday night in Knoxville, Tennessee: Ashley Monroe joined Miranda Lambert, in town on her Livin' Like Hippies Tour, to sing "Heart Like Mine."

"We should start a 'we need beer' campaign," Lambert says to the crowd, before hoisting up her pink cup and proclaiming, "I'm gonna have one for all of ya." The toast is met with rowdy applause, but there's an even bigger reaction in store when Lambert introduces her "best friend" Monroe – a Knoxville native.

Lambert and Monroe have a history with this particular "drinkin' song," as they wrote "Heart Like Mine" together with Travis Howard for Lambert's 2009 Revolution LP. Monroe's time on stage is brief — only about two and a half minutes — but they tear through the misbehaving rabble-rouser, trading off the verses and soaring together on the choruses.

Monroe recently released "Hands on You," the first single from her upcoming third LP, Sparrow, which was produced by Dave Cobb. Lambert's Livin' Like Hippies Tour stops Friday night at the Rupp Arena in Lexington, Kentucky.