MUSIC Aimee Mann and Michael Penn in Concert:

In the opening song of Aimee Mann's concert with husband Michael Penn, she sang, "God knows it's not safe with anybody else," introducing an interdependence with her spouse that highlighted this nearly two-hour evening of emotional exploration.

On the surface, the evolution of the artists suggest two immiscible types of music. In the 12 years since her departure from the '80s new wave band 'Til Tuesday, Mann has matured from a big-haired rock star to a subtle, incisive songstress. Even "Voices Carry," the song that catapulted 'Til Tuesday into heavy rotation on MTV, sounded more meditative in its current incarnation, with Mann giving more weight to the nuances of the vocals rather than biting off the edges of the words with the attitude she embraced in the '80s.

Penn's music, on the other hand, has retained the mix of Beatles-esque pop catchiness and the lyrical legerdemain worthy of Dylan that has been a hallmark of his music since his first album in 1989. From the verbal barrage of "Brave New World" to the pensive ramblings of "Bunker Hill," Penn challenged the audience not to hum along to the witty songs.

These external differences dissolved when the two took the stage. Mann and Penn bridged the gap between folk and pop. Their voices wove together seamlessly, as did their songs. As the pair bounced their unique take on life's little (and not-so-little) roadblocks off of each other's backing vocals, a unity emerged. The audience was watching two people who had found each other in the tumultuous world of music and used their spouse to magnify the truth inherent in their songs.

Onstage, both Mann's and Penn's music packs even more of an emotional punch than it does on disc. Penn achieved the emotional presence he lacked in the studio, giving songs like "The Whole Truth" the emotional desperation that matches the lyrics. Meanwhile, Mann, powerful even on her recordings, brought her music to a whole new level. While "Wise Up" smoldered on the _Magnolia_ soundtrack, Mann's haunting vocals against the starkness of the piano sent chills down my spine.

The evening was not without its humor. Stand-up comedian Paul F. Tomkins participated in what Mann called "acoustic vaudeville." In between songs, Tomkins improvised the artsists' innermost feelings, from an extended meditation on Penn's obsession with the word "popsicle," to Mann's dependence on the Internet for song ideas. Although Tomkins joked about Penn's second thoughts about the tour ("she said it would be just like a honeymoon--New England in the dead of winter!"), the audience could see just how untrue this was. The wamth between the two on stage was genuine, and no amount of winter weather could chill it.

In addtion to highlighting their newest material, both artists dove deep into their catalogs, with Mann playing crowd-pleasers "You Could Make a Killing" and "That's Just What You Are" (from the _Cruel Intentions_ and "Melrose Place" soundtracks respectively, as well as her 1995 release _I'm With Stupid_). Penn brought out his biggest hit, 1989's "No Myth," with a twist: he let Mann share lead vocals. The duet sounded natural, as did the entire collaboration between these two phenomenal artists whose chemistry and love made Saturday an evening to remember.

If you missed their show this past weekend, don't make the same mistake again. Make sure to catch them when they come around again this summer.