Stranglers break out of punk mould with classical and ballet LONDON (Reuters) - For a band that thrives on taking risks, moving The Stranglers' music from the mosh pit to the orchestra pit was an easy decision. The fact that the punk veterans, more used to fans thrashing around to their songs, are also working on a ballet based on of one their albums just adds to the spirit of adventure. The Stranglers were named last week as among the line up of the 118-year-old BBC Proms, performing their music with the London Sinfonietta on August 12, as organizers aim to attract a younger crowd to Britain's largest classical music festival Bassist Jean-Jacques Burnel, one of the group's founders, said he was "gobsmacked" when the BBC invited the band to join one of 92 events in the eight weeks of Proms concerts - some of the most sought after tickets in the London entertainment year. It has never been done before. I am still in adventure mode and anything that I haven't done is a box to be ticked," Burnel told Reuters in a pub by the River Thames, wearing black skinny jeans and dark sunglasses. "I can't think of many more prestigious events in the world musical calendar," he said, adding it was yet to be decided which of the band's songs would be played at the event. Burnel said band had always sought out risks and challenges since forming in 1974, releasing their debut album "Rattus Norvegicus" in 1977 and 16 others, as well as 23 hit singles such as "Golden Brown," "No More Heroes," and "Peaches." He describes the ballet, based on 1981 album "The Gospel According to the Meninblack" as a mix of "Frankenstein with Madame Butterfly" - although it is still very much a work in progress and could take years to complete. We are entering uncharted territory here. Can you be an old punk? But while the creative juices are flowing anything is possible," said the 61-year-old. Over the decades the band has come and gone from the spotlight, with a quiet period after original singer and guitarist Hugh Cornwell left in 1990. There has also been a few line-up changes. The group now comprises Burnel and two other longstanding members, keyboardist Dave Greenfield and drummer Jet Black, who turns 75 this year and is often replaced by Jim Macaulay due to ill health. Guitarist Baz Warne joined in 2000. Burnel said he was starting to think The Stranglers had reached the end of the line a few years ago. But then the band enjoyed a resurgence in popularity, releasing their 17th album "Giant" last year and performing at a string of festivals - where the fans dancing right at the front in the throb of the speakers have changed as the band has aged. "We have a loyal bunch of fans who have grown up with us and some more recently who have discovered us," said Burnel, hobbling on crutches after a knee operation. All the old punks with the baldy heads are being pushed to the back and the mosh pit is full of teenagers. He said they had mellowed over the years, as has their sound from the growling aggression of the early punk years. We are not looking for punch-ups all the time. At one time we had an expression that 'truth is provocation' so we would just wind people up to annoy them," he said. Do they have an expression now? "Just survive another day," he said.