Music: Turn on the DIY charm

Gomez Empire, Shepherd's Bush, London Super Furry Animals Academy, Brixton, London Longpigs Heaven, London

In the past 18 months, Gomez have released two albums, won the Mercury Music Prize, and been so highly acclaimed that even Plumbers' Weekly ran an article on how splendid they were, just so it wouldn't feel left out. It's right and proper, then, that the five scruffy Southport students of a year ago have been made over into designer-labelled rock gods and that their concerts are now well-oiled, big-budget stadium extravaganzas.

Only joking. Gomez could still be mistaken for trainee librarians. They still wear untucked T-shirts and trainers. And it's still incredible that these affable nerds should be capable of churning up such brawny, bayou- dwellin', moonshine-sluggin' rock music. The enigma is embodied by Ben Ottewell. He looks as if he had his glasses knocked off almost every day at school, but his voice can be as big and gruff as that of a bear on 40 cigarettes a day.

Gomez's non-image may be one reason why their record sales don't match their reviews. But it's not just a lack of tattoos and stubble that is letting Liquid Skin slide out of the top 40, despite the critics' best efforts to hold it back. The fact is that the album can be an alienating listen. Just when you're tapping your foot to a tune, Gomez will hit the brakes and change time signature. Just when you're singing along, they'll throw the lead vocal to another member of the band. It's all very well to applaud the deftness with which they slip between a dozen different tempos and genres per track, but this relentless complexity can leave you with the feeling that a basketball team are amusing themselves with a game of pig-in-the-middle over your head.

In concert, it's a different matter. Gomez's virtuoso chopping-and-changing is much more accessible when you can see it in front of you - and when you can see how much they obviously enjoy it. It's fascinating to watch the group juggling instruments (metaphorically, I'm afraid), to watch three of them lining up in a row to clap the Spanish rhythm of "Las Vegas Dealer," and to watch two of them playing on different halves of the same synthesiser.

Gomez have retained the informal DIY charm they had in smaller venues, but they've boosted their efforts to include the audience. In particular, Tom Gray, their keyboardist/ guitarist/ singer, is always skipping along the lip of the stage or inviting our participation with some cheesey banter.

The show dipped in the middle, sinking under the weight of one intricate, semi-acoustic folk-rock groove too many, but you can forgive any band who start their encore with a David Hasselhoff tribute slide show.

Super Furry Animals are another group who must prefer to read their press cuttings than their bank statements. Their fame doesn't match their critical standing - and for reasons quite similar to why Gomez are in the same situation. SFA's undoubted ability to write pop hooks is tempered by their unfettered imagination and, for better or worse, their propensity to bound away on loopy detours when you least expect it.

Their music is a Heath Robinson contraption. Glam rock is bolted to bug- eyed psychedelia, electronic bleeps are soldered to steel drums, techno is screwed to nursery rhymes. It's a delight; if their latest album, Guerrilla, doesn't raise a smile, then no record will. That said, it's obvious why it hasn't sold more copies. It's too self-indulgently odd for mainstream success; and while no one would want to curb SFA's creativity, it would be nice if they were more ambitious. Being experimental and irreverent is all very well, but the challenge, surely, is to be experimental and irreverent ... and have hit records.

No one could accuse SFA of being too weirdly complicated in concert. Quite the opposite. On Wednesday they reduced oddball ditties to dull, punk-rock thrashes and reduced themselves from eccentric pioneers to a garage band with a Welsh accent. Their sun-kissed melodies were in there somewhere, but they were buried deep beneath the plodding, amateurish drums, Gruff Rhys's rough falsetto, the venue's gym-hall acoustics and the group's refusal to re-create the technicolour arrangements of their albums - two comedy trumpeters notwithstanding.

There was none of Gomez's matey empathy with the audience. Instead, we had to watch a conveyor belt of lumpen songs grind by with no variation in pacing or dynamics. After a while, my mind wandered to all the crackpot ideas that make SFA such a diverting bunch of people to have around. They sponsor a football team. They've turned up at festivals with a customised tank and an inflatable cartoon devil as big as a house. They hid a CB radio glossary in Guerrilla's packaging. As the evening's ordeal continued, I found myself wondering: they haven't paid a group of lookalikes to murder their tunes, have they?

Completing our trilogy of indie Brit bands who sell fewer records than they should do are the Longpigs. Their debut album, 1996's The Sun is Often Out, did fairly well, but after that they disappeared, leaving me with just two abiding Longpig memories. The first is their singles, "Lost Myself" and "She Said", both of which were epic, post-grunge anthems with a rogue strain of celtic pomp; it's impossible to hear either track without imagining yourself in a stadium waving a tartan banner. The second memory is that, when he was on stage, Crispin Hunt would come across as an arrogant toff with a chip on his shoulder. This was understandable - he has gone through life with the name Crispin Hunt - but off-putting, all the same.

With their second album, it looks as if the Longpigs might fly, after all. Mobile Home is the hangover after the first album's drug-buoyed high. The melodramatic grandeur - "cape-swirling", in their words - has been dented and shaken, and the self-disgusted lyrics are by someone for whom the sun isn't out very often at all. U2 with less self-importance, James in a strop, the Radiohead you can dance to ... Mobile Home's tortured torch songs and funky glam struts boast the double whammy of Richard Hawley's skewed, Television-inspired guitar and Hunt's sobbing and soaring voice, which is - once you've got past the Thom Yorke and Bono comparisons - redolent of David Bowie singing about Mars and Roger Waters singing about walls.

Seeing the Longpigs live confirms that these are not Britpop also-rans, but an intense, intelligent guitar band with fire in their pork bellies. The gig wasn't quite a triumph, mind you. Many of the songs still have a tendency towards celtic bombast, and Hunt still has what you might call a losing personality. Anyone who has seen the comedian Simon Munnery in his League Against Tedium character may be interested to learn that there is a ranting megalomaniac just like him in real life.