Even though she closed out her set by reminding us that one is still the loneliest number, Aimee Mann stayed pretty damn lonesome-sounding even when she had a singing partner with her for much of Sunday's kick-off to a two-night stand at the Dakota Jazz Club.

Wry New Jersey pop/punker Leo opened the show but remained for the duration. First, Mann joined him for the second half of his set, and then he joined her during the middle of her 75-minute performance. In both instances, they played a pair of songs they co-wrote together for a new album due next spring under the duo moniker The Both. "It's a power trio," they repeatedly quipped.

Starting with "You Can't Help Me Now" during Leo's set, the new tunes proved to be a little more up-tempo and Elvis Costello-ish than Mann's norm, but also more downbeat and dark than Leo's typical fare. He joked that they're mining sonic territory between "doom-folk and recession-rock," which is actually a pretty apt assessment.

Their between-song banter was way more light-hearted and off-the-cuff. They explained how they titled another new song "The Gambler" hoping to pick up some of Kenny Rogers' uncashed royalty checks. Joking that the sound of the Dakota's clanging glassware meant that they were supposed to play a "kiss song" (as in a wedding kiss), Leo then played a few bars of Kiss' "Lick It Up," which then prompted Mann to recount the one time she met Gene Simmons in a recording studio – "where Kiss was working on a live album," she recounted (which wasn't a joke). Suffice it to say Mr. Simmons was not much of a gentleman to the slender blonde songstress.

During Mann's set, the conversation turned to the Bronze Fonz statue in Milwaukee, which apparently looks rather elfin and effeminate and was partly the inspiration for another Both song titled "Milwaukee." Leo stuck around to play guitar for "Save Me," rounding out her backing band with pianist Jamie Edwards and bassist Paul Ryan. "Labrador," the evocative single from Mann's latest album "Charmer," was a highlight early in the set. Edwards played an especially vital role turning "Red Vines" into more of a sentimental, swaying gem at the start of the encore.

Mann and Leo will be back at it tonight at the Dakota, and they are also Both scheduled to perform for a taping of "Wits" for Minnesota Public Radio at the Fitzgerald Theater on Dec. 5. Here's the set list Mann played on Sunday:

Going Through the Motions / Red Flag Diver / Soon Enough / Labrador / You Could Make A Killing / Ghost World / Borrowing Time / Milwaukee (Both song) / No Sir (also Both) / Save Me Wise Up / 4th of July / Lost In Space / The Fall of the World's Own Optimist / One (Harry Nilsson cover) ENCORE: Red Vines / How Am I Different?