LOS ANGELES: US television network CBS may have warned stars not to show too much skin on stage Sunday at the Grammys, but the music industry's A-listers tested the limits in body-conscious, revealing gowns.

Jennifer Lopez, whose plunging barely-there green Versace gown at the 2000 Grammys provided a red carpet moment for the ages, pushed the dress code to the edge with a daring black dress that covered most - but not all - of her.

“They didn't say anything about leg!” she said on the red carpet ahead of the main event, her toned bare leg and shoulder on full display in her asymmetrical Anthony Vaccarello ensemble.

Later on stage, Lopez joked: “As you can see, I read the memo!”In an email leaked to media outlets, CBS warned those appearing on the Grammys stage at the Staples Center in Los Angeles to “please be sure that buttocks and female breasts are adequately covered.””Thong type costumes are problematic. Please avoid exposing bare fleshy under curves of the buttocks and buttock crack,” read the letter from CBS's Standards and Practices department to representatives of the stars.

The letter continued: “Bare sides or under curvature of the breasts is also problematic. Please avoid sheer see-through clothing that could possibly expose female breast nipples.”

Katy Perry clearly did not get the memo, strutting her stuff in a skin-tight cleavage-baring mint green Gucci dress, saying she was inspired by the retro glam of Priscilla Presley's look in the 1970s.

Neither did Alicia Keys, who belted out “Girl on Fire” on stage in a black dress with sheer cut-outs that definitely revealed more of her breasts than the network might have hoped.

Rihanna opted for a body-skimming sheer red dress by Azzedine Alaia, with bright red lips and fingernails to match. For her on-stage performance, she changed into a simple black evening gown that was less revealing.

Pop princess Taylor Swift glittered in a winter white goddess gown from J.

Mendel, complete with silver accents at the neck and bustline and a daring slit in the front.

In the opening performance of the night, Swift changed into a white ringmaster's costume with shorts and knee-high boots - but no curves exposed.

Kelly Rowland, the Destiny's Child singer who performed with Beyonce a week ago at the Super Bowl half-time show, sported a black Georges Chakra gown with strategic cut-outs that showed off her impressive figure.

One-time “American Idol” Carrie Underwood - a winner for best country solo performance for “Blown Away” - opted for a strapless black Roberto Cavalli with a sheer skirt.

Adele, the big winner at last year's Grammys with six trophies and a winner again Sunday, left her usual basic black at home but followed the rules, opting for a bold red floral Valentino dress with long sleeves and a conservative hem.