AT the civic reception launching this year’s Glasgow Jazz Festival a couple of weeks back I replied, on behalf of the board of directors, to the welcome from Baillie Allan Stewart. Referring to the range of programming and target demographic for the event, I noted that the twin tasks of all festivals are to establish and maintain a template that the audience recognises and appreciates while at the same time innovating and refreshing the event to spark new interest, responding to developments in the music and reacting to external pressures and events. Festival director Jill Rodger and her team had all of these challenges in abundance in the festival's 30th year.

Defining the audience for a festival is not just tricky but possibly a fool’s errand, although one that has to be undertaken to do any sort of marketing, outreach and publicity. It is, however, considerably more of a problem when the audience starts to define the event. That, it seems to me, is the difficulty faced by Scotland’s largest music festival, the Tennents-sponsored T in the Park taking place at Strathallan Castle near Auchterarder in south Perthshire this weekend. A national newspaper’s listings section this week helpfully encapsulated the problem in two paragraphs several pages apart. As one of the week’s highlights “the Scottish festival’s star attraction is its raucous clientele” while the more specific music pages sniffily named the year’s headliners and continued: “But fear not, you don’t go to T in the Park just for the music; you go for the wild party atmosphere as people compete over who can pass out blind drunk first.”

This sort of thing is plainly not what teenagers seeking parental permission for their first weekend away with chums need, and whether for commercial or more altruistic reasons, DF Concerts, who produce T in the Park, are clearly well aware of the problem. For every news release hymning the quality of the line-up and – it is important to point out – the significant role the festival continues to have as a platform for new acts, with an impressive back list of musicians for whom the event has been an important stepping stone, there will be another about encouraging responsible drinking or promoting a non-wasteful “green” event.

Nonetheless, the impression remains that T is the ultimate (sorry) “ned-fest”, where the extreme behaviour of the wilder young folks are a hazard you either live with or avoid. As one of this newspaper’s regular reviewers remarked: “I’d really like to see Calvin Harris, just not at T in the Park.”

DF tried to address this with the short-lived Connect festival at Inveraray, aimed at an older demographic, but T has remained the brand leader. But although that young audience of first-timers by definition renews itself year on year, I do wonder that if it is infinitely sustainable. Two decades on from its beginnings, there was genuine not-in-my-backyard opposition to the move to its third site, which the controversy over a last minute subsidy from the Scottish Government did nothing to help. A great deal is riding on this year’s festival proceeding smoothly, without the traffic chaos of 2015 or any other mishaps. It is telling that an event that once routinely sold out still has tickets available as I write.

But the bigger question is whether a festival that is so audience-described (contrast the come-all-ye ethos and success of the Edinburgh Festival Fringe, and its indefinable fanbase) can be truly sustainable in the long term. Tribal teenagers might at any time decide that the festival-going team is one they no longer want to run with.