Pop Live: Natalie Merchant Civic Hall, Wolverhampton

I like Natalie Merchant. Bjork may be wilder, PJ Harvey more scalding, Alanis Morissette has got a better marketing campaign, and Tori Amos has a piglet clamped on to her breast. But Natalie Merchant has got... what?

Let's examine the evidence from Wednesday night's show in Wolverhampton. She's got a band in desperate need of rehearsal: false starts, lacklustre playing, ugly work from a pretty drummer - all in the opening number. She's got an audience who might be in danger of tapping a foot to the music if somebody would only confiscate their Prozac prescriptions. They would chomp the heads off live wildebeests rather than heave themselves up and dance. (When Merchant finally tempted a few of them into the aisles during the encore, they were the ones with all the rhythmic capabilities of a conga line in an old people's home - isn't that always the way?)

She's also got dance moves handed down from Michael Stipe, like that thing where he divides the air up with a karate-chopping hand. And she has a line in banter that's as thrilling as her fans. "This is a nice place to play. Do you agree?" Pause. "We were in France a coupla days ago. We played this song there too." Pause. "I'm low on patter tonight." Snooze.

And she's got her voice. That voice. It's a pity that Kellogg's Corn Flakes beat her to the tag-line - "Have you forgotten how good she is?" - because it would have been perfect for her. The longer those albums by her former band, 10,000 Maniacs, rest at the back of your memory like guests that you wish you hadn't invited to the party, the more you forget the devastating, rejuvenating, white-hot power of that voice, with its twang and sustain, and its terrific density - it's a voice that you could wade through, or sleep in.

It can work miracles. The new single, "Wonder", is essentially a pleasant, airy dollop of Angel Delight. But Merchant's total conviction, the way she hurls her body, heart, lungs and all other major organs into the music, lifts the song high above the rooftops. She even makes the "ooo-ooh" bit sound profound.

I think Merchant has been obscured by the awful mediocrity of 10,000 Maniacs. They were the sort of band you used as a barometer for picking your pals; you know the sort of thing - you wouldn't want to give your home phone number to anyone who likes kd lang, Red Dwarf or 10,000 Maniacs.

But her solo album, Tigerlily, is the most desperately moving work of her career. And her new-found solo status has done her back catalogue no harm: she treats the songs from the old days ("That other band I was in," she goofs, "I can't remember their name") with a fury that at last deserves the description "maniacal" after all these years. "Eat for Two" is slowed down, chant-like in its haunted melancholia. You haven't absorbed its full despair until you've seen Merchant thump at her belly with balled- up fists as the line "My folly grows inside of me" leaves her lips like a dying breath. It's the blues all right - the baby blues. "These are the Days" travelled in the opposite direction, toward calypso and jazz, while Merchant travelled around the auditorium on a little jog.

The band had picked up speed too. The guitarist Jennifer Turner was finger- picking good, with a knack for long and winding guitar solos that should earn her an 18-night residency at the Royal Albert Hall. Even Peter Yanowitz had loosened up, so that by the end you liked his vigorous drumming as much as you liked his face. At two hours, it was all too loose. The covers - "Son of a Preacher Man", a tepid "Fever", and a Joni Mitchell mini-medley abandoned "because her melodies are impossible" - were perfunctory. But "Ode to Billie Joe" was dark and deadly, with funk and swamp-rock trappings. Time to throw your preconceptions off the Talahassee Bridge.