Dame Shirley Bassey has said her famous voice failed her in the months after the death of her daughter.
Samantha Novak, 21, was found face down in the River Avon, near the Clifton suspension bridge in Bristol, in 1985 and Dame Shirley said she damaged her voice by singing through her grief.
The Welsh singer has always maintained that her daughter's death was not an accident or suicide, and says she rushed into performing to deal with her feelings.
Speaking to David Walliams in a BBC special celebrating her career as she approaches her 80th birthday, she said: "It was just devastating. I went home and after a week of being alone I woke up one day and said, 'I have to go back on stage, this is killing me'. I don't know what I would have done with myself.
"And then came the show, and I walked on the stage and I opened my mouth to sing Goldfinger - nothing came out.
"What had happened was, instead of staying home and grieving and getting it out my system, that I was singing it (grief) through the songs and I probably wasn't breathing in the right places and panicking.
"For six months I couldn't sing at all. Then a vocal coach - Helena Shenel, who I thank so much - I just worked with Helena doing these vocal exercises strengthening my vocal cords, and after the year she said, 'do you know, I've discovered you've got another octave that you never use. I've never heard you sing that high!'
"And she did my spirit the world of good and my soul, and I went back on stage."
Dame Shirley also told David she had to stop her first manager from changing her name to something he saw as "more showbiz" like Betty Bassey.
She said: "We came to blows because he wanted me to change my name. And I said, 'but if I change my name and I become famous nobody will know who I am!'
"I was dead set against it, and I am glad I did put my foot down."
David Walliams Celebrates Dame Shirley Bassey airs on Christmas Eve on BBC One at 9pm.