Music: Naturally 7 at Fairfield Halls, Croydon

Naturally 7 is a group of seven guys who go on stage with nothing but their clothes and microphones for company, yet sound as if they have a whole band supported them.

At first you might think it's from a backing track but no, all the noises come from the singers, who imitate everything from bass and drums to electric guitars and harmonica in a style they name vocal play.

"Most people often use the word a cappella, that's singing without instruments," says Roger Thomas, who was a founder member of the band a decade ago.

"But we define vocal play as us becoming the instruments and imitating bass, drums, guitars, everything.

"People will close their eyes and feel like these instruments are being played but there will just be the seven of us on stage and seven microphones.

"Everything you hear is going to be created.

"We knew we were good at singing a cappella but didn't feel like we had our own sound and were looking for that unique thing.

"The first four beats of a Beatles song you know it's them, the same with The Bee Gees and Earth Wind and Fire and we wanted something unique for us.

"My brother could imitate drums so we started from there and found out other people could do this and that instrument and it just kept evolving.

"It was a risk but it's one of those thing that was worth it, now we have a thing nobody else has."

In the last few years they have achieved a great deal of success with their style, most notably a video of them singing on the Paris metro viewed more than seven million times on YouTube.

"We didn't think anything of it at the time," says Roger.

"The record company put it out there and once people discovered it, wow, it changed our lives.

"For a while every country we went to the video got there before we did.

"It's got so many views because people realise it's live and off the cuff.

"It shows the reality of how people react and I think that is what people like to see, they like to see the conversion.

"There's one guy people talk about all the time who refuses to let the music come in but there were others that even started participating."

The guys performed at London's Pigalle earlier this year and were approached by Coldplay's Chris Martin and producer Brian Eno afterwards, who announced themselves as big fans.

Since then they have spent time in the studio together and Roger admits he would love to do a collaboration.

"We don't know if that will happen but we would like to for sure," he says.

"Quite a few of us are big Coldplay fans.

"We are fans of any band or musician that has their own path and do really good music."

Seven Naturally 7 facts:

- This is the first time they are performing as part of the London Jazz Festival.

- Roger and his brother Warren used to live in Stoke Newington.

- They had a number one single in Germany, collaborating with Sarah Connor on Music is the Key.

- They performed at Quincy Jones' 75th birthday concert.

- This year's Wall of Sound was their fifth album and made the UK top 30.

- They were the support act for Michael Buble's tour in 2007.

- They met Prince Charles after performing at the Royal Variety Television Show last year.

Naturally 7, Fairfield Halls, Park Lane, November 22, 7.30pm, £14.50. Call 020 8688 9291 or visit fairfield.co.uk