ROCK / Pushing back the envelope: Elvis Costello and the Brodsky Quartet, live

'THIS is the first night of the Juliet Letters tour,' says Elvis Costello, standing on the stage of Glasgow's Royal Concert Hall with the Brodsky Quartet around him. 'And boy, are we nervous.' And at this point, people in the auditorium are looking a bit twitchy too, if only because, in the venue's tensed hush, it's painfully obvious that someone, somewhere, at some point, is going to call out for 'Oliver's Army'.

In the meantime, Costello and the Brodsky Quartet do battle with their nerves. And, though the nerves put up a decent fight during the first number, 'For Other Eyes', they're just about routed by the burst of applause at its close. The Juliet Letters is an album of songs modelled on different kinds of letter (a piece of hate mail, a suicide note, a billet-doux, etc) and written for strings and voice. Hence these early jitters - unusual for Costello, who normally looks pretty bullish in front of an audience. The worry here is, presumably, that the whole package might get returned to sender. In fact, the audience - standing up at the end, shouting and whistling - receives it more in the manner of an unexpected cheque.

On The Juliet Letters, a self-taught pop musician meets a crack classical team. This is not an exercise you could whole-heartedly recommend for just any of Costello's peers. (Graham Parker and the Tallis Scholars, anyone? Wilko Johnson and the Consort of Musicke?) But for one thing, the letter form seems exactly the kind of notion to fire up Costello the lyricist - a whole batch of verbal formalities ('eternally yours', 'I must close now', 'If you're reading this', 'By the time you get this letter') just waiting to be twisted around. (Those proper formalities are also something that the feel of a string quartet is peculiarly equipped to suggest and subvert.) And for another, Costello's voice fits him for the part.

Recent Costello albums have seen him developing a peculiar high-pitched wolf's howl, for use at moments of extreme excitement or annoyance, which clearly was best momentarily set aside for this project. But he has always been able to generate a narked edge which sits well with strings at their most energetic; and, in calmer moments, the quantity of breath in his voice blends easily with the noise of the bow on the gut.

Somehow Costello, Michael Thomas, Ian Belton, Paul Cassidy and Jacqueline Thomas have managed to come together without inflicting on us some kind of dire Pop Go the Brodskys-type album and without producing, even worse, Elvis Costello: His Sensitive Side. Aggrieved Costello fans may maintain he's just cruising for serious credibility with some fashionable musos. Classical objectors will claim the Brodsky's are out shopping for the youth market by slumming it with a rocker. But the album sounds like a proper collaboration, in that what were probably recognisable differences of approach at first meeting, have fused in the process.

Take, for instance, the tune for 'Jacksons, Monk and Rowe': with its straightforwardly poppy cadences, it is the most obviously Costello-like song on the album. And yet it was written by the Quartet's Michael Thomas, which bears out something Costello has said about his writing collaborations with Paul McCartney - that partners frequently end up switching roles, playing to the other's strengths.

Still, getting up to this kind of thing in the privacy of a studio is altogether different from turning out the results in public. For Costello, up there at the lectern, there's no guitar to hide behind. He doesn't even have the security of a microphone to lean into - just one of those nearly invisible ambient pick-ups, perched on a thin stalk a few feet in front of him. So he contents himself with standing with his hands folded together at chest-level, or occasionally picks the music up and holds on to it for support.

Complicated duties render the Quartet almost static, but for the flailing bows. But at the edgy piece of cello-abuse that opens 'Swine', Costello is beginning to rock slightly on his hips. This show commits him to a greater variety of vocal exertions than anything he has yet done. He has to fake the mad aunt who narrates 'I Almost Had a Weakness', which he does with phlegmy venom. He has to hit the strenuously high climax of 'Taking My Life in Your Hands'. Yet, as the evening moves on, he finds breath to work a few of the lines for laughs - most enthusiastically during 'Damnation's Cellar', which envisages a machine for returning the dead to life and wonders whom one might use it on: 'The critics say Nijinsky, the dancer, of course / While the punters would probably prefer the horse.'

For an encore, the five play an arrangement of Kurt Weill's 'Lost in the Stars'. Weill has often been mentioned in connection with The Juliet Letters, if only because he provides a convenient catch-all tag for anything remotely angular-sounding or strung out across tricky, brittle rhythms. In fact, if anyone pops up regularly between the lines here, it is Randy Newman. The final goodnight number is an eerie 'Scarlet Ribbons', arranged to incorporate thin traces of 'True Love'. It has Newman's way of bringing a sweet melody up against a slice of strings and making it sound doomed. The call for 'Oliver's Army' had come between songs 14 and 15. It was laughed down.

(Photograph omitted)