The Edinburgh International Festival (EIF) has traditionally been a bastion of classical music and opera.
But under new director Fergus Linehan, the event will feature rock, pop and modern music as well as seeing its dates move for the first time in nearly 20 years.
Mr Linehan, who unveiled his new vision for the EIF yesterday, said that although orchestral music would remain "at the centre" of the programme, he wants the festival to include more modern music.
The fan of Scottish bands such as Belle and Sebastian, Mogwai, King Creosote, Arab Strap, and acclaimed Scottish electronic band Boards of Canada will also makes moves to include Celtic music to the programme.
"As a 21st century, multi-genre arts festival, it is important that we take a more consistent and comprehensive approach to other musical genres, both to reflect the way that cultural appetites have change and also to reflect where important work is being made," he said.
Mr Linehan, currently director designate until October, also said that from 2015, the festival will move its dates forward to August 7-31, to coincide with the Royal Edinburgh Military Tattoo, the Edinburgh International Book Festival, the Edinburgh Art Festival, and, crucially, the Fringe.
The Fringe board are "very relaxed" about the synchronised dates, and Kath Mainland, director of the Fringe, said: "The dates for the Edinburgh International Festival are a matter for the EIF to decide, but it is undoubtedly the case that Edinburgh in August, and indeed throughout the year, provides a blend of world class festivals unrivalled anywhere else.
"We know that it is this combination of distinct festivals that sets Edinburgh apart."
The last time dates were changed at the August festival was in 1998, when the Fringe moved forward a week, leading to controversy at the time.
On modern music, Mr Linehan said: "They will probably kill me because I haven't approached them yet, and it is presumptuous, but I can tell you artists who I like: Belle and Sebastian, Mogwai, King Creosote, Wedding Present, Arab Strap, and Boards of Canada, I could go on and on and some of them don't perform live anymore.
"There's a lot of interesting work in the Celtic area, and just being Irish and being in Scotland there's an immediate connection for me but also there's a number of people that came to me with some thoughts on it that I found interesting.
"Classical music will still be the centre of the programme, there is no dilution of it.'"
On the date change, Mr Linehan said "the days when French or German companies shut down in August are over, and the rationale for those dates being the way there are is not there.
"I come at this as an audience member...what is unique is that the festivals happen at the same time. That makes it not just the greatest arts festival in the world, but the greatest event in the world."
Mr Linehan also unveiled several events at next year's festival, including Antigone starring Juliette Binoche (see story, right), a production of Mozart's Marriage of Figaro, a major opening event and a celebration of the Edinburgh Festival Chorus.
Other changes will see the end of "themed" programmes, as they have been under Sir Jonathan Mills.
Mr Linehan will also address how opera is staged , and said: "We need to think of ways we can weave opera through the three weeks of the programme that is elegant and exciting."