There are all kinds of fascinating architectural ramifications to this concerning the fusion of building types, but for the moment let’s concentrate on that big glass roof. Remember Richard Rogers’ “Mexican Wave” glass-roof design of the mid 1990s for London’s South Bank? The one that was going to turn all the windswept concrete bits into sheltered promenade spaces? The one that succeeded the 1980s cut-and-paste Terry Farrell masterplan? Rogers’ design may have been a very different shape from Vinoly’s latest in Philadelphia’s - it had to be, to negotiate all the existing lumps and bumps of buildings on the South Bank - but the concept was by no means dissimilar.

As it happens, Vinoly is one of the many architects with a cancelled South Bank project in his portfolio. Within the most recent Rick Mather-designed masterplan for the arts ghetto, Vinoly was in a play-off with an avant-garde British outfit called Foreign Office Architects to build a significant chunk of it. Namely, the part on the open land upstream of the Royal Festival Hall, overlooked by the big wheel of the London Eye. A new concert hall and film centre was mooted.