Audiences, not actors, are the stars of the show in the world of Sing-a-Long-a productions, which are dedicated to well-loved musicals including Annie, The Rocky Horror Picture Show and Hairspray.
The Sound of Music show, which was established 10 years ago, is a screening of the classic Julie Andrews musical in glorious technicolor and complete with subtitles - so the entire audience can sing along to their heart's content!
Marketing director Simon Thomas explains: "The Sound of Music was our very first show in London in 1999 and it took off big time. We were inundated with requests from musical fans asking us to bring the show to their home towns and, 10 years later, we are still going strong.
"The first half of a show is a vocal warm-up led by the evening's host, who takes the audience through what will actually happen during the show. Previous hosts include Graham Norton and Charmian Carr, who played Liesel Von Trapp in the original film. She has been incredibly supportive and she always gets the crowd very excited!
"Julie Andrews has said she admires the format and has hinted that she might come along - but in disguise!"
The film starts in the second half of the show, with lyrics on screen, and this is where the audience takes centre stage. Simon says: "People have so much affection for the film, and the singing is the part everyone loves, but there is also a tongue-in-cheek aspect, too.
"Although it's not compulsory, most people wear fancy dress and the show includes a costume competition, in which everyone is invited on stage to show off their fabulous tailoring skills. It's just really good fun and the cast and crew enjoy themselves as much as the audience.
"We are not about intellectual or spiritual enlightenment - it's all about encouraging everyone to let go and enjoy themselves. With so many people suffering financial problems at the moment, that's just want they need."
Sing-a-Long-a's format has been a hit across the globe, from Malaysia to Australia and New Zealand and all over Europe. It even filled the Hollywood Bowl in Los Angeles!
"The Hollywood Bowl show was an incredible sight to see," says Simon. "Ironically, the only place the show hasn't been a success is Salzburg in Austria, where the film was originally shot. I think people there are still trying to avoid any association with the Nazis and perhaps the film, and the show, brings up too many painful memories.
"Apart from that, we have been delighted with the show's success, and have no plans to say 'So long, farewell, auf wiedersehen, goodbye'! We will carry on as long as the audiences want us to. The Sound of Music, like most other classic musicals, transcends all ages - it really is timeless."
* Sing-a-Long-a Sound of Music invites you to dress the part at The Beck on Saturday, January 31, from 7pm. Tickets cost £15 from the box office on 020 8561 8371 or via www.becktheatre.org.uk
