That has been the Lyric experience to date, interesting in its crackpot way but not exactly a refulgent dialectic between the architectural mores of the 19th and 20th centuries. It comes as no surprise to find that the building is one of the more humdrum works from the practice of that nonpareil commercial architect of London's post-war boom, Richard Seifert. Nor that it is built of the cheapest possible materials, a concrete block made of concrete blocks. The final non-surprise, again very much in period, is that the whole development - shops, offices, car park, council flats, theatre - was part of a vaster plan for Hammersmith, inevitably involving high-level walkways, and equally inevitably abandoned before the high-level walkways were built. Which left, high up in the air inside its utilitarian grey overcoat, the interior of Frank Matcham's 1895 Lyric.

It's Matcham's year all right, Matcham the architect of the restored Hackney Empire and London Coliseum theatres in east and central London respectively. The late 1960s battle to "save" the Lyric - a victory which in fact meant demolition in 1971 of all but the rococo auditorium interior, which was put into storage to be clipped back together years later - nonetheless marked a turning-point in attitudes towards the popular theatres of the Victorian and Edwardian efflorescence. Suddenly, they were seen as perhaps having a value. Rather as Victorian pubs were incongruously left marooned amid housing-project wastelands, so the patrician planners of the time decided that the people should be allowed some remnants of their treasured culture, sanitized of course and with a modish "studio theatre" added. So the Lyric remained, borne aloft in a calcareous concrete embrace, until enough Lottery money came along to allow a bit of architectural payback. Thus Rick Mather, architect to many an art gallery and university, restaurant and private residence, has brought the Lyric back down to earth and given it a street presence again.

Mather is one of the first on anyone's list when it comes to stitching damaged bits of urban fabric together. "Giving something to the street" is practically the motto of this urbane American, London-based architect, who is also the author of the most credible masterplan to date for the South Bank cultural quarter. Although the Lyric is a tiny job by his standards these days - the $100m expansion of the Virginia Museum of Fine Arts is occupying his studio greatly at present - it bears a particular hallmark of his: it's so simple, so apparently obvious.