John Squire's divorce from the rest of the Stone Roses must have been an acrimonious one indeed. Why else, when he needed a lead singer for the Seahorses (Leeds Town and Country Club, Tues), would he take up with a performer who is as different from the Roses' Ian Brown as possible?

Where Brown was effortlessly stylish, Chris Helme is a tousle-haired scruff. Where Brown patented his own brand of prowling, ice-eyed cool, Helme is a grinning, foot-tapping fellow with an acoustic guitar, who stops singing mid-song to joke about his sore throat, and to conduct the audience's shout-along. He got the Seahorses job after being spotted busking outside the York branch of Woolworth's, and he proves once again the old adage that you can take the man out of the High Street, stick him in a band with a living legend, fly him to Los Angeles to make a chart-topping album, and put him on stage in front of 1,800 fans - but you can't take the High Street out of the man.

Of course, Helme is only to be applauded for refusing to copy his predecessor's style. There is, after all, only one Ian Brown (and that's Liam Gallagher; Brown himself comes a poor second). And we could add to the above list of contrasts the fact that where Brown sang like an exhausted goat, Helme has a reasonably strong, if indistinctive voice, and he acquits himself particularly well during his own solo spot.

No, it's not off-putting per se that the singer of the Seahorses doesn't think he's in the Stone Roses; what's off-putting is that the guitarist thinks he still is. Squire has given up experimenting and has become a quicksilver blues player, cranking out flash licks as if every song were Led Zeppelin in full-on rock mode - or as if every song were from the Roses' fatal Second Coming album, which comes to the same thing. But the songs aren't like that. Almost every one of them sounds like the novelty track on an Oasis album. Even "Suicide Drive" is chirpier than anything the Stone Roses ever did. Squire, taking the title of the Seahorses' debut album literally, wrote most of the songs on Do It Yourself (Geffen) himself. But these half-realised Britpop ditties seem to have more to do with Helme - who still has the cheery demeanour he must have used to charm 20p out of passing shoppers - than with Squire, who is every inch the aloof, skinny guitar hero: he strolls across the stage in a world of his own, with no expression on that fragment of his face which protrudes from under his German Shepherd fringe. This lack of understanding between the band's two key members makes for perplexing, unsatisfying listening. (The rest of the band, in case they were feeling left out, were absolutely fine.)

Journalists have been inclined to assume that the Seahorses will always be John Squire's baby, the role of the other three members being to scrape the ground and declare that they are not worthy. But on Tuesday, the Seahorses didn't seem to be Squire's band at all. They seemed to be band that was started up by a few inexperienced mates of his, and he seemed to have dropped by to help them out and show off a bit, before heading back to his proper job.

Ben Harper is not only an astonishing guitarist and one of America's finest young songwriters; he is quite possibly the most sensitive man in the world (see how he responded to the crowd's screams at the Shepherd's Bush Empire on Wednesday by putting a hand on his heart and watching us with big, worried eyes). It's an attribute that sometimes works against him. On the 27-year-old Californian's latest album, The Will to Live (Virgin), his sensitivity borders on wishy-washiness, and dilutes the fire and focus that made 1995's Fight For Your Mind such a classic. And when, in concert, he picked at the acoustic guitar strings with his thumb, and delivered his intelligent lyrics in a tender, halting whisper, he could barely be heard over a crowd that was waiting for the rest of his band to return, and for Harper to unleash his soulful holler.

The Empire was not the venue for him. He stayed seated as he played the acoustic guitar and the Weissenborn - a hollow-necked slide instrument - so that those of us standing downstairs could see little more of him than his Dennis the Menace frizz. The intimacy of last year's Jazz Cafe show was sorely missed. All the same, though ... the funky band, the palette of sounds, the resemblance to Bob Marley that is more than physical, the political indignation - and all that sensitivity. You can't complain.

Jean Michel Jarre was at Wembley Arena on Monday, promoting Oxygene 7- 13 (Dreyfus) - his remember-when-I-used-to-make-successful-records equivalent of Tubular Bells 2. Nothing much had changed since Oxygene part une, 21 years ago. There were "Chopsticks"-style keyboard lines, a few Euro-beats, the bleeps and pings of a Space Invader machine, and lots of whooshes and washes. Whatever Jarre's press releases may tell you, you won't see his fans at Prodigy, Orb or Underworld gigs, unless they've turned up to give their offspring a lift home at the end of the evening.

The former futurist is now behind the times, but his Martian muzak would still work well enough if you were simultaneously oohing and aahing at the fireworks and lasers of his outdoor extravaganzas. Unfortunately, Monday's indoor concert was a bargain-basement version, and with only a slide show and some strip-lights to distract us, we actually had to listen to the music.

The Seahorses: Norwich, University of East Anglia (01603 505401), tonight; Forum, NW5 (0171 344 0044), Fri; Manchester Academy (0161 275 4815), Sat.