Arab Strap, Mean Fiddler, London

You can't expect to have a "good time" at an Arab Strap gig - not in the conventional sense anyway. The band underlined the irony by naming their 2000 live album Mad For Sadness. Arab Strap write very slow, very sad, and often very rude songs. This limits their chances of giving the punters a fun night out.

The last time I saw them, I wondered why anyone had come. Unable to recreate the delicacy of his witty sung-spoken tales of sexual woe live, Aidan Moffat had resigned himself to drunkenly mumbling his way through, while guitarist Malcolm Middleton lamely beefed up the sound by making free with distortion pedals.

But now things are different. It is a testament to Arab Strap's distinctiveness that their style has varied so much over the course of five albums with so few people noticing. Moffat, meanwhile, has become a compelling frontman.

Lumbering on to the stage in a heavy coat more suited to Alaska, Moffat grabs the mic and sings, loudly, with what I am going to describe as soul. His Glaswegian growl is hardly a soul voice, but the conviction he brings to the line "we can't waste what we can't even start..." at the climax of "Meanwhile, at the bar..." makes it a proper tearjerker.

After that, things get big. Ample use is made of Jenny Reeve's violin and Allan Wylie's trumpet, recalling Spiritualised's finer moments. But "Scenery" could be REM if it weren't for Moffat, while the current single "The Shy Retirer" has a garagey-disco feel to it - appropriate for a song that rhymes "moaning" with "serotonin". The older numbers, barely murmured on record, have taken on melodies where none existed.

But it's no party. When the violin screeches dissonantly as Moffat howls out the allusions to domestic violence in "Act of War" ("the fact is you've always been clumsy / whether it's with tables at your work, or with my heart"), Joy Division come to mind. This is music as horrific psychodrama. At other moments, though, the epic sound is clear and beautiful, serving as a kind of emotional pedestal for the banal situations the lyrics so frankly describe. "Soaps" makes dissatisfied mutual dependency sound like Hollywood romance.

It's true that by the end of the gig Moffat's voice has started to grate, and the overall effect can veer towards self-parody - especially, I imagine, for those unfamiliar with the records. It cannot be easy to transmit such negative, wordy music live, but this time round Arab Strap are making a mighty fine fist of it. The songs' honest, witty precision is such that just watching other people in the crowd mouth or giggle along fosters a rather wonderful sense of collective empathy. You find yourself smiling.