It’s hard for a group to make it in country music. Just ask Little Big Town.

Now in its 20th year, the harmonizing country quartet finally made its first arena headline appearance in the Twin Cities on Thursday at Target Center. As entertaining as the performance was, things were abundantly clear why Little Big Town hasn’t gotten bigger.

There is no one lead singer.

Nearly every country group that has made it big has a singer who is the focal point. That’s been the case with the Dixie Chicks, Zac Brown Band and Alabama, the biggest country group of all time. Fans like a single personality to focus on, especially in concert.

But Little Big Town insists on being the Fleetwood Mac of country, with four spotlighted voices and without the interband drama. (LBT’s Karen Fairchild and Jimi Westbrook are married to each other, and Kimberly Schlapman and Phillip Sweet have their own spouses.)

Four lead singers doesn’t necessarily beget a problem; after all, Fleetwood Mac has triumphed with three on the microphone. But with Little Big Town, none of the four is a commanding voice. Instead, it’s all about the harmonies, which were musically satisfying and often gorgeous, notably on “Can’t Go Back.”

The harmonies were often reserved for the choruses. That meant a featured singer on most songs and, frankly, there weren’t enough memorable turns.

Westbrook and Fairchild have strong but undistinctive voices. Sweet has an appealing Gregg Allman-like soulfulness, but he’s limited. And Schlapman is similarly limited with her Dolly Partonish voice that lacks arena oomph.

Still, LBT has figured out how to put together an engaging and rewarding show by varying the energy and vocal combinations and throwing in some surprises. Opening with Elton John’s “Rocket Man” may not have been as spectacular as Tim McGraw kicking off his 2004 St. Paul show with Elton’s “Tiny Dancer” standing at the soundboard, but for LBT, Elton meant liftoff.

The 90-minute show reached a peak during a deftly done stripped-down set on a satellite stage in the bowl end of the arena. Not only did the four singers, sans their four backup musicians, get intimate on the hits “Your Side of the Bed” and “Sober,” but they paid tribute to the recently departed Don Williams (“Lord, I Hope the Day Is Good,” “I Believe in You”), Glen Campbell (a reverent and romantic “Wichita Lineman”) and Prince (with a verse and chorus of a delicate “When Doves Cry,” which drew a huge response from the 9,000 fans).

That little acoustic foray seemed to spark the return to the main stage for fervent ensemble lead vocals on “I’m with the Band” mashed up with a savvy snippet of the Beatles’ “With a Little Help from My Friends.”

Then it was time for fireworks — vocal and musical, thanks to a forceful band and such popular hits as “Tornado,” “Day Drinking” and the dark, swampy Fleetwood Mac-ish “Boondocks.” But LBT dialed it down, too, for the Grammy-winning “Better Man” and “Girl Crush,” during which Fairchild finally stood out as a singing star.

The show’s best moment, though, may have happened at the end of the main set when Fairchild and Schlapman spontaneously broke into the chorus of Demi Lovato’s recent pop hit “Sorry, Not Sorry.” Suddenly, they stepped out of their roles and engaged in the joy of harmony singing. What joy!

The concert had two opening acts, Midland and Kacey Musgraves.

Smartly performing entirely on the satellite stage, Midland came across as an above-average harmony-loving male band from Texas that can sound alternately like the Eagles or Alabama.

Beloved country maverick Musgraves, 29, has somehow managed to transform herself from a kitschy cowgirl with clever, skewed lyrics about small-town life to Courteney Cox’s lifeless little sister in a black cocktail mini-dress and platform heels singing pedestrian love songs worthy of a 14-year-old Taylor Swift.