Flashback: See U2's Country Alter Ego the Dalton Brothers

Group dresses up to cover Hank Williams' "Lost Highway" in 1987 Joshua Tree tour performance

At a 1987 Joshua Tree tour stop in Los Angeles, U2 surprised audience members by performing Hank Williams' "Lost Highway" as the Dalton Brothers.

In late 1970s Ireland, between the emergence – and eventual collapse – of disco and the rise of punk and new wave acts, country music in the Emerald Isle was mostly popular with the older generation. Among young concertgoers and record-buyers, however, one of the most buzzed-about acts was a group that would soon fully embrace American culture, including classic country music. First formed as Feedback in Dublin in 1976, Paul "Bono" Hewson, David "The Edge" Evans, Adam Clayton and Larry Mullen Jr., would go on to worldwide acclaim as U2, one of the most popular and influential rock acts of the past 35 years.

In the spring of 1987, when the band released their fifth LP The Joshua Tree, the group launched an expansive North American and European tour that ran through the remainder of the year and introduced fans to what would be their first (and, thus far, only) Number One hits, "With or Without You" and "I Still Haven't Found What I'm Looking For." The LP topped the charts for nine weeks and has since sold more than 10 million copies.

The Joshua Tree Tour, which would be the band's first to visit larger arenas and stadiums across the U.S., was captured on film for the concert documentary Rattle & Hum and the group's subsequent live album of the same name. During the cross-country trek, U2 visited such iconic locations as Elvis's Graceland mansion and Sun Studios in Memphis, recording new tunes at the latter, including the gospel-influenced "Angel of Harlem" and "Love Rescue Me," as well as Woody Guthrie's folk classic, "Jesus Christ," and "She's a Mystery to Me," a song they penned for former Sun Records legend Roy Orbison.

Having immersed themselves in American music and culture throughout the year, the group confounded fans at a trio of their shows on the tour with the surprise appearance of a country band called the Dalton Brothers, who took their name from the notorious Dalton Gang of the 1890s, perpetrators of a wave of train and bank robberies in the Old West. Wedged between sets from such legit opening acts as Los Lobos and the BoDeans, the modern Dalton boys ("Alton," "Luke," "Duke" and "Betty" Dalton) took the stage in cowboy hats, wigs and western wear, with some audience members reportedly unaware they were actually Bono, Edge, Larry and Adam in disguise. A detailed bio on a Dalton Brothers webpage declares "We play two kinds of music: Country and Western" and notes that the group took inspiration from country legends including Willie Nelson, Johnny Cash and Loretta Lynn.

In the above clip from the band's November 18th, 1987, show at Los Angeles Memorial Coliseum, Alton Dalton affects an exaggerated southern accent and tells the crowd, "This is just like Farm Aid and we like it that a-way. You people are beautiful people." Alton then introduces his "kid brother," Luke, who takes the lead vocal on "Lost Highway," a mournful, gospel-tinged tune Hank Williams recorded in 1949. In spite of having become so closely associated with Williams, the song, which was relegated to the b-side of his Number One smash, "You're Gonna Change (or I'm Gonna Leave)," was actually penned by early country star Leon Payne. As their performance rolls on, the Daltons' version of the "tchoon" (as the Edge refers to it, slipping back into his native accent) takes on the loose, rollicking feel of a Saturday night at a neighborhood pub in the group's homeland. Even Bono's, er, Alton's cheesy wig and goofy remarks to the audience ("It's great to know that in Los Angeles it's love, not money, that makes the world go 'round") can't disguise the fact that the band members shared an affection for the roots music that left their shores and eventually settled in the mountains of the eastern U.S. before ultimately spreading back throughout the world.

U2 have announced plans to mount a stadium tour this summer in commemoration of The Joshua Tree's 30th anniversary. Opening acts will include Mumford & Sons, the Lumineers and OneRepublic. There's no word yet on whether the Dalton gang will ride again during the upcoming tour.