LAST Saturday's opening night of Alan Cumming Sings Sappy Songs at this year's Edinburgh International Festival was one of those occasions about which folk used to say "if they'd dropped a bomb" before that joke stopped being at all funny. If anyone there had paid for a ticket, they were likely in the minority, on what was self-evidently "guest night", so much so that those of us who would actually be turning in a piece of work by writing about it were in danger of being choked by their own halo of virtue. Cumming, to his credit, carried on as if he was performing to a "normal" audience of paying punters until he got to the point where he had to acknowledge that two of the people who featured in his latest hilarious showbusiness anecdote – theatre director John Tiffany and choreographer Steven Hoggett – were actually in the room.

Alongside the celebrities, politicians, artists performing elsewhere on the Festival and Fringe, producers, promoters and humble journalists, were people like Assembly's Bill Burdett-Coutts and Karen Koren of the Gilded Balloon. I didn't see Ed Bartlam and Charlie Wood of Underbelly, but if they weren't there, they were assuredly standing in the same part of Castle Terrace as myself the following night for Deep Time, the huge audio-visual spectacle to a soundtrack of Mogwai music, along with 27,000 other folk. That event, of course, followed last year's Harmonium Project, which used the Usher Hall rather than Edinburgh Castle as its canvas, and which was in part designed to make people think about that venerable concert hall, central to the EIF programme since its beginnings, but into which, new director Fergus Linehan noted then, a large number of Edinburgh people had never set foot.

A few may well have paying their first visit on Monday evening, drawn by a chance to see and hear veteran Australian character comedian and all-round erudite bloke Barry Humphries, who was presenting an evening of Weimar Cabaret music from between the First and Second World Wars in the company of the titfer-sporting Australian Chamber Orchestra.

If the people who run the biggest venues on the Fringe hadn't noticed before – and of course they will have – there was an obvious message in the opening days of the 2016 Edinburgh International Festival. In the argot of international diplomacy, Linehan has parked his tanks on their lawn. Of course they were all invited as guests to Cumming's opening. Having stolen their clothes, it would have been rude not to ask them along to see how well they suited the previously matronly EIF. And show off a bit. As well as the cabaret stuff, Linehan has also swiftly filled a gap left for contemporary non-classical "art" music by the demise of previous initiatives on the Fringe, as Neil Cooper explained in this section a few weeks back, and he'd noted the success of Glasgow's Celtic Connections and grabbed a bit of that territory too. In just two years of programming, it has come to seem insane that no-one saw the possibilities for audience growth that the EIF was previously, slightly preciously, ignoring. In these days of collegiate endeavour under the Festivals Edinburgh banner, it hasn't even caused a row. At least in public.

And here is the perfect answer to snooty folk who think that such programming has no business in their Festival. The morning Queen's Hall recital series – perhaps the most "elitist" element of every Festival – is having its most successful year ever, with as many tickets sold a week ago today as in the whole of last year. That is the knock-on effect.