Chris Martin duets with Rihanna on new Coldplay album (BLOG)

Chris Martin revealed that Rihanna sings on Coldplay's upcoming album, "Mylo Xyloto," on a duet entitled "Princess of China." Martin had Rihanna in mind as the perfect guest vocalist, but was too nervous to ask her when they first met.

He tells Britain's The Sun, "The album is designed as a whole piece. It has boy and girl lead characters and top of our list for the girl part was Rihanna ... but it took a while to pluck up the courage to ask her."

"We did a show in Las Vegas and I met her and said, 'Do you think there's any chance?' I was very Hugh Grant-like and spluttering about it," he explains. "She has such an amazing voice and it's so different to mine. When the vocal happened I thought 'Wow, you sound different,' but I think that's also because she was singing a different song to what we are used to hearing from her."