I’ve always been wowed by the way that k.d. lang can make her voice, seemingly without effort, do pretty much whatever she wants it to. And she’s always been a highly polished, confident stage performer.

But perhaps more than ever before, something that was also on display Friday night—when lang performed with her recently formed band, the Siss Boom Bang, at Hill Auditorium (as part of the Ann Arbor Summer Festival)—was an unabashed and infectious sense of joy.

This would seem at least partly due to lang’s recent return to her alt-country roots, via the album “Sing It Loud,” and her fruitful collaboration with the five-person Siss Boom Bang (which lang noted was now celebrating its one-year anniversary with her).

“We’re all in love with each other, as dysfunctional as things can sometimes get,” lang told the packed house. “I love these guys.”

Dressed as a cohesive unit—with SBB members wearing red shirts covered with long-sleeved, button down black shirts and black pants, while lang wore a white shirt beneath a black one, accented with a red neck scarf—lang and the Siss Boom Bang offered a broad range of tunes during the regular set and two encores. (The show in total ran 90 minutes.)

For in addition to performing all 10 songs off “Sing it Loud” (plus the bonus track “Hungry Bird,” from the deluxe version of the CD), lang performed the irresistibly breezy “Summerfling,” “Miss Chatelaine,” a cover of The Little River Band’s “Reminiscing,” and a rocked-up, aggressive take on her biggest American hit, “Constant Craving.”

Lang danced and cheekily teased the audience during the show’s upbeat numbers, but one of the evening’s hands-down highlights involved a far more somber moment. For as lang concluded her whimsical, gorgeous cover of the Talking Heads’ “Heaven,” SBB pianist Daniel Clark delicately segued into Leonard Cohen’s “Hallelujah.”

Many artists are drawn to the song, of course, but lang’s always-stunning combination of raw vocal power and emotional vulnerability establishes her version as among the most definitive. So while a prolonged standing ovation in the middle of a concert like lang’s is rare, it nonetheless happened as “Hallelujah”’s last notes faded, and audience members (myself included) swiped at a few stray tears.

A far more unexpected highlight came when, for the second encore, lang returned to the stage with one band member wearing a washboard, and another carrying an accordion. As all five members of SBB formed a half circle around lang at the microphone, she said, “Ladies and gentlemen, we would like to perform for you an old-timey k.d. lang song.”

With this, the performers launched into the goofily fun, quick-tempo song, “Pay Dirt,” off lang’s 1987 album “Angel with a Lariat.”

Indeed, since lang's first band, the Reclines, accompanied her in the '80s, during the earliest part of her career, she's gone solo and adhered to a strictly adult contemporary path in her music. Her most recent artistic collaboration with SBB, and her return to the music that originally inspired her, seem to have newly invigorated the singer/songwriter, making her a far more personally engaging performer.

For after welcoming the crowd and noting that it was Canada Day, and that Canadians were everywhere, she said that freaks were everywhere, too. “I’m sure there are some here in the audience,” said lang. “We are in Ann Arbor, after all, and being at a k.d. lang show pretty much puts you in that category automatically. Some of you are probably raising little freaks. … Just make sure to raise that kid to be confident in who they are.”

Finally, mention must be made of The Belle Brigade, the fantastic, folk-rock brother-sister act (Barbara and Ethan Gruska) that opened for lang (and inspired this 9-months-pregnant woman to dash, as much as that’s physically possible, to the lobby to buy a CD).

Backed by a four-piece band, the Los Angeles-based duo, during their half hour-plus set, electrified the crowd with their vocal harmonies (calling to mind Indigo Girls and Simon and Garfunkel) and contagious energy, particularly on songs like “Sweet Louise” and “Belt of Orion.” If you missed them Friday night, check them out online. My guess is that, regardless, you'll be hearing more from The Belle Brigade down the road.

Jenn McKee is the entertainment digital journalist for AnnArbor.com. Reach her at jennmckee@annarbor.com or 734-623-2546, and follow her on Twitter @jennmckee.