Shirley Bassey credits Gary Barlow, Rufus Wainwright and Pet Shop Boys with bringing her out of retirement - because she was committed to spending the rest of her life away from the studio until she was presented with a new batch of songs.
The result is the 72-year-old star's first new material in 20 years on her latest album The Performance.
She tells Billboard magazine, "I'd really retired, to tell you the truth, and was just coming out for special occasions. These writers have brought me back. Only that could have done it, and it was a challenge, because you wouldn't have thought they were my songs.
"I took them on holiday with me, and I would say, 'I can't do this, they're too difficult'. But I was listening to the way the writers were singing them, and trying to sing in their key, which never helps.
"It wasn't until I actually went into the studio, with a piano, and put my voice on, that I started to get excited. I could hear myself. I'm always up for a challenge, and it paid off."