THEY have a unique sound and a devoted fanbase and they have graced some of the most prestigious stages in the world from the Hollywood Bowl to the Royal Albert Hall.

Next week Pink Martini will be in Manchester on the final date of their UK tour celebrating 21 years together.

The 11-piece orchestra fronted by vocalist China Forbes almost defies description. Even the band themselves struggle to explain what they do in a sentence.

“I think you just have to come and see it for yourself,” said China. “I call what we do old fashioned pop, it’s like Sinatra-era pop with the orchestrations and the language of the songs.

“But really I think that people just need to have an open mind and come to the show and be transported.”

A Pink Martini show may include samba rhythms, African-inspired songs, Forties big band arrangements and classic pop.

“Because we started out as a completely independent band we didn’t have to conform to any marketing plans of any kind,” said China, “and we still don’t.”

For China that can be particularly testing - the band’s repertoire includes songs in over 20 different languages.

“On one album Thomas (Lauderdale, the band’s founder) said he wanted me to sing an Egyptian song in Arabic. I just though I can’t do this but the next thing I knew we had recorded it and I’ve sung it live many times since.

“He always believes I can do things I don’t think I can so now when he says I can do something I have to believe it.”

Although she sings songs in many different languages, China admits she can’t speak them all.

“You have to understand the sentiment in every phrase whatever the language,” she said. “It’s hard. I sometimes feel like need to insert a new memory card to keep up with all the songs over the years.”

It was Thomas’ desire to do something different which led to the band forming in Oregon in 1994.

“Thomas has always wanted to make records that he would want to listen to rather like a DJ cobbling together all the different influences and sounds he likes,” said China.

“He calls it exquisite musical wallpaper because he wants it to be something you can play all the time in the background of your life and I think he’s achieved that.”

But don’t think for a moment that Pink Martini are not a vibrant live act. The live shows are an immersive affair with first class musicians playing a wide variety of instruments with China an engaging frontwoman.

“We’ve always been incredibly spontaneous on stage,” she said. “It makes it more exciting for us and the audience. If the setlist remains static that’s not as much fun.

“I always try and change the way I introduce some songs to keep it fresh and with other parts of show there’s nothing remotely planned and that’s just the best feeling when you’re in the moment with everybody.”

Pink Martini appeal to fans across the generations.

“After the show it’s great to hear someone say they got into our music through their parents or for parents to say they heard our music being played by their children,” said China. “There’s not a lot of music that appeals to so many different generations.”

Pink Martini, Bridgewater Hall, Manchester, Monday, October 31. Details from 0161 907 9000