The Welsh diva singled out Queen Bey for criticism, admitting she was shocked when she laid eyes on her much-talked about 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.”
Shirley also offered some advice to Sam Smith, who is recovering from an operation to repair a ruptured vocal cord.
“Sam Smith lost his voice, get a coach and do these operatic notes that opera singers do, that I did when I lost my voice many years ago,” she said.
“I was with an opera singer for a year doing vocal exercises only and I found I had an octave more.”
The ‘Lay Me Down’ singer is expected to make a full recovery from his surgery.