The music icon revealed the news ahead of Sunday's headline performance.
Dame Shirley Bassey has spoken out about modern pop stars, telling them to wear more clothes and concentrate on singing.
Stars including Beyonce came under fire from Bassey, who said she was shocked when she saw the star's Met Gala gown.
“It’s like they’re all in competition with each other for who can wear the skimpiest outfit,” she said at the Variety Shooting Stars book launch.
“In my day it was for the stage only, you didn’t go out looking like that.
“When I saw the Met Ball, excuse me, when I saw Beyonce’s gown... I think you have to leave some things to the imagination,” she said.
"Yes, my gowns were sexy, with a cut-out and a slit here, but I didn’t show everything.
“These girls are talented singers – they don’t need that but they feel they do.
“That’s the sad thing about it. Go in the studio and sing your heart out, get a vocal coach and strengthen your vocal cords.”
Do you agree with Dame Bassey? Or should pop stars be able to wear whatever they want?
Watch Shirley Bassey perform ‘Goldfinger’ below: