Country superstar Keith Urban has always been a T-shirt and jeans, let-his-hair-down kind of guy. Except maybe when he accompanies his wife, actor Nicole Kidman, to some special showbiz event. Thus it was no surprise when Urban played it fun and loose on Sunday night at the Fine Line in Minneapolis.

That's right. The Fine Line, a downtown club with a capacity of 650. Urban, who headlines arenas and festivals these days, squeezed in a barroom appearance — an underplay in music industry parlance — after big gigs in Milwaukee and Cadott, Wis., and before he plays a NASCAR-related event in Chicago next weekend.

How loose was Urban? He was so loose that he was honoring requests by the second song. He was so loose that during a long unplanned medley that started with his hit "Somebody Like You," he found a guitar riff that led him into Talking Heads' "Road to Nowhere" but he improvised the line "I don't know the words to this song" to the melody. As he kept the guitar riff going, he asked for requests. Someone shouted "Eagles." He responded, "You're yelling a band, not a song."

Someone else piped up "Take It Easy" so Urban obliged even though it didn't fit with the guitar riff, which he kept playing while he sang the unmatching traditional melody. As he jokingly dropped from a high voice to a low one, he naturally segued into Johnny Cash's "Folsom Prison Blues" before returning to "Somebody Like You." Then he asked people to sing along — first those in the balcony, then those in the back of the club and finally "guys named Gary." Urban laughed. It was hard to tell who was having more fun — Urban or the crowd.

Urban was so loose that when he played "Wildside," his brand new single that his four-person band just learned at rehearsal, he spontaneously grafted on Survivor's "Eye of the Tiger" and Stevie Nicks' "Edge of Seventeen." Afterward, the band and Urban were laughing that they pulled it off.

It was that kind of night for two hours at the Fine Line.

The evening began with Urban, 56, thrusting his fist in the air, promising a loose performance and delivering an eight-minute solo acoustic treatment of "Long Hot Summer," one of the 22 No. 1 singles he's racked up since 2000. He took a bass heavy solo that slowly started to rise, moved into an arpeggiated section and built into the kind of rising passages Urban is known for. The Aussie/American is one of country music's most versatile and adventurous guitarists in concert and staked his claim on the opening number.

Always more spontaneous onstage than most Nashville stars, Urban further manifested his guitar prowess on the ensuing "'Til Summer Comes Around," a request ("we haven't played that in forever," he said), during which he was joined by bassist Jerry Flowers and drummer Terence F. Clark. The power trio was the perfect format as they kicked out the jams.

Urban seasoned "Where the Blacktop Ends" with a Middle Eastern guitar figure before bringing out percussionist Michael Gonzales and singer/multi-instrumentalist Maggie Baugh to complete the band. However, as the night wore on, Urban's guitar solos became more concise. Frankly, his fretwork was more expansive and rewarding last year at his outstanding performance at the Minnesota State Fair grandstand.

It was only $50 to get into the Fine Line (tickets were sold two days in advance), two bucks less than the cheap seats for Urban at the fair. In this intimate environment, the fortunate fans got to hear hits (highlights were "You'll Think of Me," the southern soul "Blue Ain't Your Color,"), silly covers (Jimmy Buffett's "Margaritaville" by request, Steve Miller's "The Joker" with a taste of Bob Marley's "All in One,"), serious covers (Miley Cyrus' "Flowers," Prince's "Raspberry Beret") and a nifty bluegrass-y instrumental ("Rollercoaster").

This was the first underplay by a major act at the Fine Line since Maroon 5 offered a modest acoustic set there in 2007. But Urban, who did a similar club show in Dallas in May, seemed more generous, comfortable and ready for these kinds of cool things. That's why he was selling a T-shirt that generically declared "Keith Urban Club Gig."