The curtain went up, the band started playing and, off in the shadowy wings of the giant stage at Xcel on Friday, Kix Brooks pushed Ronnie Dunn onstage. It was a playful moment out of the spotlight, but it could have served as a metaphor for Brooks & Dunn's performance and their Last Rodeo Tour.

You could see it in Dunn's tired face, indifferent body language and terse patter: He's done, done with Brooks & Dunn, country's most successful duo, after 20 years and 20 No. 1 hits. It was an arranged marriage to begin with (by a record exec), and now Dunn is ready for D-I-V-O-R-C-E.

Dunn, who will turn 57 before the Last Rodeo Tour ends in August, apparently wants to launch a solo career and, I guess, try to be Alan Jackson without a hat. But Brooks, who just turned 55, was still alive and kicking, wondering if he wasn't Brett Favre reconsidering his latest announced decision.

This was an odd and erratic farewell. Brooks & Dunn's St. Paul swan song lacked the passion and spirit of the Judds' finale and the freshness and spontaneity of Alabama's Twin Cities farewell. In fact, those rank as the best metro gigs ever by the Judds and Alabama; Brooks & Dunn's "We're Done" show felt too much like just another B&D concert in front of 15,468 delighted fans.

Brooks obviously cared; he always has. He performed with energy, charm and purpose. Dunn, principal lead singer, was in good voice, putting just the right ache in his sweet tenor, but he didn't seem to be enjoying himself. For too long, he seemed determined to keep a chasm between himself and Brooks onstage.

Not until one hour into the two-hour set did the "best friends" (Brooks' words) finally seem like a buddy act. They joined each other at the end of a runway and dug deep into their catalog for "How Long Gone" and "Ain't No Way to Go." Dunn stuck by Brooks' side to sing "Red Dirt Road," their 2002 smash, arguably their most country-sounding uptempo hit. Then Dunn crooned the big ballad "Believe" and finally his passion matched what Brooks had done on his solo turn on "You're Gonna Miss Me When I'm Gone" (which could be Brooks' theme for this tour).

After "Believe," a clearly emotional Brooks gave a brotherly fist bump to Dunn's shoulder. But the long tall singer just walked away, returned to the main stage and rocked out with "Hard Working Man," with the chasm returning. After having entertained effectively but separately, they finally carried on like a true duo on the closing run of "My Maria," "Brand New Man" and a bluesy "Boot Scootin' Boogie." They ended with a well-earned high-five -- and then walked offstage one at a time, Dunn before Brooks.

For a set list, go to www.startribune.com/artcetera. Jon Bream • 612-673-1719