The city's annual book festival also hit its stride on Saturday with the promise of a global discussion on the importance and place of literature in society.

The Edinburgh International Festival EIF.L and book festival combine with huge gathering of artistic talent in the Fringe, the ever-popular Royal Military Tattoo and the city's art galleries in the largest annual gathering of the arts in the world.

Moves to promote the Edinburgh scene to Olympic visitors appear to have paid off, with sources saying EIF ticket sales this year were up around eight percent over 2011, and an increase in sales also noted by the Fringe and book festivals.

Scotland's festivals are worth some 250 million pounds annually to the country's economy, with the Fringe alone - which this year brings a record 23,000 performers to Edinburgh - worth around 140 million pounds to the city.

Edinburgh will also host a conference organised by the EIF and the British Council of more than 30 ministers of culture from around the world at the Scottish parliament on Monday and Tuesday to discuss the place and importance of culture in the global society.

The EIF's opening concert on Friday night to a packed audience at the Usher Hall was described by The Scotsman newspaper as "a glorious gold-standard performance".

Music critic Kenneth Walton said the seldom-heard setting by English-born Delius of the work of German poet-philosopher Friedrich Nietzsche as "the musical equivalent of a glitter-strewn ticket-tape parade".

He had high praise for the Royal Scottish National Orchestra and an augmented Edinburgh Festival Chorus, all under the baton of Sir Andrew Davis.

The EIF is presenting a wide range and challenging selection of opera, theatre, music, dance and debate through its run to September 2.

The book festival, in cooperation with the British Council, is staging a debate with 50 leading international authors between August 17 and 21 covering a range of topics from censorship and politics to style versus content and the future of the novel. The debate will then travel to events across the world over the next 12 months.

Some 800 writers from 44 countries are taking part in 750 events at the book festival, which runs to August 27. (Editing by Paul Casciato)

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