Popular entertainer Madonna is listed at 20 in the Time Out 'Power 100' survey, on the grounds that she is 'London's most prominent special envoy abroad,' whatever that is supposed to mean. But influence she certainly has, as a recent incident at the Sir John Soane Museum illustrates. Turning up one day and unable to jump the queue to get in, her aides subsequently called the museum. The result? A special evening opening for the diva and her entourage. I hope it was as enjoyable as Richard MacCormac's party the week before, when luminaries including Sir Neil Cossons, new head of English Heritage, and Southwark' development director Fred Manson (No 22 in the Power 100) were in attendance.