It is "sad" that Madonna is "obsessed with being so young", according to Welsh singer-songwriter Donna Lewis.
Donna, best known for her 1996 hit I Love You Always Forever, said the drive to look young and the sexualisation of the music industry were off-putting.
She said: "It's all about sex basically and how you flaunt yourself in front of the camera. I won't be doing that. I won't be taking my clothes off."
The 42-year-old, originally from Wales, was not a fan of 57-year-old Madonna's tribute to the late pop star Prince, who died in April.
She said: "As a performer she is amazing, but to see her on the Billboard Awards singing that Prince song - I just felt, it's just so sad.
"I don't know why she has to be so obsessed with being so young and doing young stuff."
Donna added: "She's such an amazing performer, she should do what's right for her.
"But sometimes I feel, seeing her just come and sing - I'll probably get slated about this, but just singing a song about something that needs to be sung so beautifully, Nothing Compares 2 U - it just didn't work. It was just too sad for me."
Getting older in the music industry is a minefield, Donna said.
She joked: "I haven't had a face lift, and I probably need one! It is hard because even when I was first doing I Love You Always Forever promo, every interviewer would ask me: 'How old are you?' I said, 'But do you ask the guys the same question?' No.
"Always obsessed with how old are you and what you look like.
"So getting older, I mean it is hard, and you look at yourself in the mirror and you see the jowls coming and the wrinkles. But I just realise, that's what it's like, I'm happy in my own skin and I'm older and that's the way it is."
She added: "I am actually glad I had my success when I did, because I don't think I would like to be a young artist coming out now because it's just so hard... it is just about how you look.
"That was always important, but it was never as important 20 years ago as it is now."
After some time away from the music industry, Donna is back with a new album - Brand New Day - and a UK tour.
The music is very different to her old synth pop sound, with more of a jazz vibe. Alongside original music and covers of songs including David Bowie's Bring Me The Disco King and Fred Neil's Everybody's Talkin' At Me, there is a newly-reworked version of I Love You Always Forever.
Looking back on her hit from 20 years ago, she said: "I remember the first time I ever heard it, and that was the biggest thrill ever.
"I'm just grateful that it still gets airplay I have to say, because I know a lot of songs come and go, and this cute little nursery rhyme song of mine still gets played."
Brand New Day is out now.