A minor celebrities, tabloid photographers and well-heeled media types squeezed into the opulent Art Deco catacombs of London's Savoy Theater for the oddest of opening nights on Thursday. Kicking off a two-week residency those dry-witted pop intellectuals,the Pet Shop Boys, finally arrived in the semi-mythical London milieu that they eulogized with their debut single West End Girls all of 13 years ago ­ and still they didn't seem entirely comfortable there.

Subtitled Somewhere, these shows provide a rare live sighting of this elusive and largely studio-based duo. Antipathetic to touring, or indeed promotion of any kind,Neil Tennant and Chris Lowe will almost certainly lose money on the venture. But, as a profile-boosting exercise, it might just counter the disappointing sales of their most recent album, Bilingual.

Tennant and Lowe have always straddled the boundary between showbusiness and conceptual art. Despite frequent protestations to the contrary, they are clearly much more than mere entertainers. The collision of Lowe's dynamic disco arrangements with Tennant's erudite, pithy lyrics may have produced many of the best singles of the past decade, but they can also seem maddeningly aloof and hobbled by critical theory.

Hence their Savoy residency, a glitzy extravaganza on the surface but a far stranger beast beneath. Conceived by the artist Sam Taylor-Wood, the stage design owed more to gallery installations than to West End musicals. Flanked on either side by giant video walls running real-time footage of revelers chatting and dancing, Tennant and Lowe appeared to move between stage and screen at carefully synchronized intervals.

Although these attempts to expand orthodox notions of pop presentation are laudable, this intimate theatrical setting did not necessarily enhance the duo's somewhat rigid performance style. Tennant often seemed wooden and uncomfortable, while Lowe's pulsating soundscapes deserved more decibels. This was particularly true of such one-time show-stoppers as Yesterday When I Was Mad or Can You Forgive Her, whose restless energy clearly demanded less sedate surroundings. However, the softer and warmer contours of the duo's more recent, Latin-flavoured singles Se a Vida É and Before adapted more comfortably to the Savoy's understated elegance.

The show's latter half seemed to give Tennant a second wind, his reedy voice becoming a lusty roar for the crashing melodrama of The Theater. He then duetted with backing vocalist Sylvia Mason-James on a witty medley of It's a Sin and the disco classic I Will Survive. At this point the crowd could contain itself no longer and rose en masse for Boys' new single, an irreverent and highly charged disco remake of Somewhere, from West Side Story.

For the encore, Tennant strapped on an acoustic guitar for a robust solo reading of Rent. Then Lowe's keyboard exploded back into life for Left to My Own Devices, with its definitive Pet Shop Boys lyric: "Che Guevara and Debussy to a disco bea". But that was written seven years ago. In 1997, Liberace and Damien Hirst to a disco beat would be nearer the mark. Nowadays, the Pet Shop boys are unsure whether they would rather be Gilbert and George or Gilbert and Sullivan.