Rock: It isn't that the Bluetones are exactly boring ...

IN 1996, when the Bluetones appeared on a TV show called The Noize, they decided to swap places with each other. "And as they all look pretty similar," boasts their press release, "only their fans could tell!"

Not the sort of thing that most bands would be proud of, I wouldn't have thought, but it's typical of the Bluetones' relationship with the public. Their second album, Return to the Last Chance Saloon (Superior Quality), is now in the Top 20, its predecessor went to No 1, and they've had four top 10 singles. But if you ask the next person you meet, I bet he or she won't be able to hum any of their songs. For a band who are doing so well on paper, the Bluetones are misty, intangible: the Invisible Band. Even the group themselves probably have to check the nametags on their boxer shorts to be sure of which of them is which.

Having seen them at the London Astoria on Monday (the band, not the underpants), all I can say about them for certain is that there are four of them. They're not smartly dressed, but they're not scruffy either. Their ballads aren't very slow, their fast songs aren't very fast.They're too wishy-washy to pull off their Led Zeppelin impersonations, but they're not poppy enough to be a pop group: whenever they chance upon a melody, they hide it before anyone notices, slipping it in at the start of a song or keeping it tucked away until the end. Mark Morriss can write some sparklingly honest and clever lines, but the songs as a whole are more like sketchy intellectual exercises than touching expressions of his feelings. As you might gather from the instrument-swapping incident, the Bluetones would rather amuse themselves than impress anyone else.

On Monday, as the drummer hunched over his kit and concentrated on keeping up the same shuffling pitter-patter all night, the tunes soon merged into one long jangle. Morriss, however, is a decent frontman - assuming it's him, and the 'Tones haven't switched identities. He bobs and weaves with a restless, nervous energy, as if he's psyching himself up backstage. The audience respond with ecstatic adoration - and good on them. I'm not suggesting they were mistaken, I just wish I could work out what I'm missing.

There's no such confusion about the identity of the Corrs. For one thing, that really is their name: Jim Corr plays keyboards and guitar, and his three sisters provide vocals, penny whistle, fiddle and drums. For another thing, if you're going to invite Mick Fleetwood onstage as your guest star, as the Corrs did at the Albert Hall on Tuesday, you don't leave any room for doubt about your choice of genre. They play the sort of mainstream soft-rock that's currently serving Natalie Imbruglia so well in Britain, and serving the Corrs so well everywhere else in the world. Andrea's strong, angsty voice tackles lyrics about the course of love running wonky, and, just to remind us that the siblings are from Ireland, the instrumental breaks could have come from a Caffrey's ad or the Titanic soundtrack. In two words: Alanis O'Morissette.

The core Corrs, plus a bassist and guitarist, are polished professionals, but not even the date - St Patrick's Night - and the interspersal of traditional airs and jigs can stop the succession of slick, frictionless songs getting a little stultifying. Only the band's natural personal charm saves the evening - that and the fact that the sisters are uniformly dark- eyed, slender and gorgeous. One reviewer likened Andrea to Posh Spice, but although the two of them share a taste in strappy black party dresses, Andrea's perfect bone structure would give her grounds to sue for libel. And while she's not what you'd call a magnetic frontwoman, her gauche, self-conscious dancing only enhances the Corrs' likeably unpretentious feel.

British stardom shouldn't elude them much longer. They do what they do very well, and if it's a choice between seeing it done by a) Mick Fleetwood, and b) three women who look like younger, healthier Courtney Coxes, then I know which I'd go for.

Now, readers, I have an incredible coincidence to report. On the very night that the Bluetones were playing at the Astoria, Jimmy Webb was beginning a three-night run two miles north at the Jazz Cafe - and the Bluetones' next single, "If", lifts two lines from Webb's 1968 classic, "Wichita Lineman"! No? Sod you, then. I thought it was incredible.

On Wednesday, Webb sang "Wichita Lineman", and all the other classics which his precocious, pretentious 20-year-old self composed, and which Glen Campbell and others performed. With an album of golden oldies to promote, Ten Easy Pieces (Guardian), he stuck to his very best material - and material doesn't come much better. This, then, is the perfect time to see him. You may have to wear a crash helmet to protect you from the names that fall thick and fast during his anecdotes, but when Webb sings his yearning folk-hymns, all traces of cabaret schmaltz are buried under rough-hewn emotion.

Bluetones: Aberdeen Music Hall (01224 626039), tonight; Glasgow Barrowlands (0141 339 8383), Mon; Cambridge Corn Exchange (01223 357851), Wed; Leeds T&C (0113 280 0100), Thurs; Guildford Civic Hall (01483 444555), Fri; Empire, W12 (0181 740 7474), Sat. Corrs: Sheffield City Hall (0114 273 5295), tonight; Northampton Derngate (01604 24811), Mon; Croydon Fairfield Hall (0181 688 9291), Tues. Jimmy Webb: Belfast Arts Ctr (01232 316900), tonight.