Each night is an adventure in unknown territory

The International Festival offers just as eclectic and stimulating a programme as the more famous Fringe

What's unusual about Macbeth at the Edinburgh Festival?

Nothing – except that it will be performed in Dutch. Or strange about Mussorgsky's Pictures at an Exhibition? Well, it is to be heard in an arrangement for two accordions. Set Dvorak's oratorio Saint Ludmila against seductive Piazzolla Quintets or Handel's Jephtha opposite Heiner Goebbels's symphonic reincarnation of urban life, Surrogate Cities, and you begin to see where Brian McMaster, the Festival's director, is coming from. He relishes the obscure, chuckling gleefully when it's suggested that while the rest of the cultural world is dumbing down, he is braining up. "I simply try to ensure that each event is a true Festival performance, often taking us into unknown territory.

"I first came here as a teenager in 1961, George Harewood's first year as Festival director, and resolved to come back every year." He's not quite managed that but McMaster is – to judge from the number of foreign Festival bosses who descend on Edinburgh each year – the experts' expert. One of McMaster's strongest memories of 1961 is of Joan Sutherland's sensational interpretation of the lead role in Zeffirelli's production of Lucia di Lammermoor. This year's plum is Peter Stein's Parsifal conducted by Claudio Abbado for which, if you're quick, you can nab one of the 100 £5 day-seats.

From Giulini and Solti conducting Rossini and Britten respectively 41 years ago, we fast-forward to 2002 and Luc Bondy's fabled production of Britten's The Turn of the Screw, Charles Mackerras conducting Donizetti's Maria Stuarda, and the third part of Scottish Opera's highly acclaimed Ring cycle. The three evenings of Scottish verse programmed in 1961 have grown into a regular national strand – eight concerts of Scottish political song this year. And in a radical new departure there's a series of unstuffy late-night concerts to attract a younger audience for just £5 a ticket into what McMaster describes "as Europe's best concert hall, bang in the middle of the clubbing centre of Scotland".

Already running, unprecedently, in week zero, the 10.30pm slot offers a wide range of classical music from Brendel in Beethoven to Carles Santos's bizarrely individual NO TO NO, new sounds by Rebecca Saunders to all-night Indian raga, Stockhausen's Stimmung and John Adams's Harmonium to Bach, Schubert and Messiaen. McMaster has gone for pieces that "pack a punch" and works or artists that, he believes, can "speak to anyone".

Programming around 180 performances in his 12th Festival, featuring more than 2,400 artists from 20 nations is, as the gnomic McMaster sees it, simply sharing whatever currently excites him. He remains unassuming, at least on the surface. Unlike his immediate pre- decessors, John Drummond or Frank Dunlop, his manner is neither contentious nor abrasive, which surely smooths his way through the mire of politics involved in keeping the 55-year-old Festival in such rude health.

"Really the structure has changed very little from when Rudolf Bing launched the first Edinburgh Festival in 1947. Whatever happened later, that astonishingly successful venture was rooted in the community. People gave up their ration cards so that visitors could eat," McMaster points out. Hotels were derequisitioned, more than 6,000 beds were offered in private Edinburgh households and residents offered up their meagre rations of coal in an attempt to persuade the miserly Minister for Fuel and Power that Edinburgh Castle should be floodlit as a symbol of the Festival and the city. It was, for four nights, and after the grim war years the dazzling moment of its lighting up was greeted as a real symbol of the Festival and the city. Something of that thrill can still be experienced more than half a century on in the musical pyrotechnics of the fireworks concert on the closing night of the Festival (31 August).

The Fringe gate-crashed the party right at the start, when six uninvited theatre companies staged their own productions in 1947. Quickly garnering a reputation for new and controversial work, the Fringe is generally credited with laying on the horror more thickly. Not, however, until Calixto Bieito's uncompromising production of Valle-Inclán's Barbaric Comedies in 2000 did the Festival really challenge the Fringe's reputation for testing the cutting edge.

While it's not certain that anyone on the Fringe this year will attempt to put out their own eyes, the Festival is unlikely to have the monopoly on the patricide, suicide and incest that inspired such a fascinating web of sounds from the Romanian George Enescu in his opera Oedipe, "the great sleeper", as McMaster refers to it, receiving its overdue British premiere in a not-to-be-missed concert performance on 18 August. The same Sophocles story crops up later in the Festival in Stravinsky's take on the plague-ridden story Oedipus Rex in a topical production by the Canadian film director Francois Girard, whose Novocento was a hit of last year's Festival.

There's a performing duck on this year's Fringe, but the Festival has a live owl on stage (Jan Farbre's Swan Lake); the Fringe has its obligatory chainsaw, the Festival boasts a musical one in Oedipe; and while some Edinburgh worthies may get their knickers in a twist over genital origami on the Fringe, others will be bending over backwards to see the Festival's highly physical body show, Boris Charmatz's Status.

Yet despite the fact that McMaster must have seen the memorable exhibition of Epstein sculptures in 1961, visual arts were quickly moved down his list of priorities, leaving Scotland's galleries to fend for themselves. This year's exhibitions range from drawings by Rubens in the National Gallery of Scotland to the vibrant colour blazing out of the larger canvases of Howard Hodgkin (he gives the University of Edinburgh Festival Lecture on 25 August) out at the Scottish Gallery of Modern Art, to the city-centre Scottish Gallery housing Wendy Ramshaw's intriguing installation Room of Dreams (until 3 September). No one has any excuse for being bored in Edinburgh in August, not in 1947, not in 1961, and not in 2002.

Edinburgh International Festival runs officially from 11-31 August, though late-night concerts at 10.30pm have already started at Usher Hall (0131-473 2000, www.eif.co.uk)