The sun finally came out for the last week of the Edinburgh Festival. Yet for more than three weeks, the Scottish capital has been the victim of diluvial rain of the kind to make even the most committed culture lover question the wisdom of the art world's annual pilgrimage to the north. There have been other questions hovering over the four-week jamboree (in effect not one, but four events sprawling through August). Ticket sales on the Fringe - some 30,000 events packed into nearly 250 unlikely venues - are down 10 per cent, partly because of the chaos caused by a new centralised ticket system which simply didn't work.
Although numbers are up for the Book Festival and have held for the International Festival, there is already a sense that this hasn't been a vintage year. The director Jonathan Mills's loose theme of "artists without borders" has produced some outstanding music, but a lot of rather dour theatre. The world premiere of Matthew Bourne's new work Dorian Gray sold out faster than any dance event in Festival history, but proved a squib rather than a real firework, all style and not a lot of substance.
The normally reliable Traverse scheduled a series of plays that reflected a society at odds with itself, such as Simon Stephens' thoughtful work, which is set in the days surrounding the London tube bombings of 2005. Though the plays have all raised challenging questions, none has been an absolute standout. It's been the same on the comedy circuit, which now dominates the Fringe; lots of good solid stand-up but not many outstanding new faces.
So if you simply listen to the commentators, you might think that this year's Edinburgh Festival has been a washout. But on the ground, it feels rather different. I am always overwhelmed by the curiosity and sense of adventure that propels audiences into everything from Devil's Ship, a one-hour play in Farsi by an all-female theatre group, to One Night Stand, an improvised musical by a group of enthusiastic Americans. One was impenetrable, the other a hoot. Both were received warmly.
If I had to find a reason for that, it would be in something that became the refrain to my own visit to the Festival: the simple power of story. I started to think about this in a charming children's show called Aesop the Storyteller, which filled in the background of the man who told the famous tales, a slave who found freedom through his words. David Harrower's bleakly beautiful 365 for the National Theatre of Scotland stages with brilliant economy some of the stories of young people in care. In a production that is both troubling and deeply moving, one girl says: "I scream my story. Either you listen or you don't."
This is theatre as testimony; using its power to give voice to people who traditionally have none. There have been many versions of this in Edinburgh this year, including Philip Ralph's Deep Cut, an engrossing study of the attempts of the families of young soldiers who died at a British army base to get a proper explanation for their deaths. Their efforts have, so far, been unsuccessful: the play, which tells their stories, is a further attempt to keep the cases in the public eye.
Monologues also abound, whether it be Simon Callow's impersonation of Charles Dickens or Britt Ekland remembering her life, or Coming Up for Air, an adaptation of George Orwell's novel. In part, this reflects the economics of the Fringe, where breaking even is doing well and a one-man operation is nice and cheap. But as you watch audiences engrossed, it is impossible not to recognise that this is part of theatre's original atavistic power: it's like a story told around a fire.
At the Fruitmarket Gallery, until the end of September, there is an exhibition of work by Janet Cardiff and George Bures Miller, which brings all these themes together. Using objects, sound and texts, this Canadian duo probe the very nature of what a story is. In one work, Opera for a Small Room, onlookers are invited to peer into a shed, constructed in the centre of a gallery, containing records and an odd assortment of old-fashioned speakers. As you watch, the records start to play, as if by magic.
You hear sounds, of a train rushing past, of a woman walking and disconnected sentences. But if you listen very carefully, you begin to understand the tragic tale unfolding. By using your imagination, you can piece together the mysterious fragments and begin to see into another life. Finally, before the lights go up, you hear applause. This brilliant, haunting piece seems to me an apt symbol of why we brave the rain and go to festivals, why we want to experience art: the stories we see, hear and tell help us, in the end, to understand ourselves.