At first glance, the idea is absurd. Unlike those others, Matcham (1854-1920) was emphatically not an architects' architect. No intellectual aesthete he. He was not even properly trained, but he married the daughter of his boss, theatre architect Jethro Robinson, and then found himself in charge, aged 24, when Robinson dropped dead. Matcham's reputation quickly eclipsed his father-in-law's. He designed scores of theatres in late Victorian and Edwardian times. And though he did build opera houses in Belfast and Buxton, most of his output was not high-culture venues, but variety theatres. Music Hall. Vaudeville. He designed for the unwashed masses, which means his architecture was populist. Highly ornamented, very colourful.

Matcham was theming buildings long before the cinemas of the 1920s and 1930s picked up on the idea, let alone Disney. And from the point of view of the purist architectural establishment, there's only one thing worse than slapping on the ornamentation: it's doing theme-park buildings. Being prolific didn't help, either: serious architects are meant to cherry-pick the commissions, not churn them out like sausages. For years, Matcham's name appeared in no dictionary of architecture. Over 80 per cent of his buildings were destroyed. He just wasn't rated.

The grandest, most ornamental and most directly themed of all Matcham's variety theatres is the Coliseum of 1904. Outside, a baroque tower borrowed from Borromini via Wren supports a rotating globe bearing its name in lights. Go through the doors, and you are in a weird neo-Rococo Edwardian vision of Ancient Rome, complete with chariots - drawn by lions - charging at you from either side of the huge proscenium arch. The dome above your head is painted to resemble a fabric canopy such as they might have stretched across the original Colosseum to shade the spectators watching the gladiators about their business.