We all know the rule about not wearing black underwear under a white top. But maybe Fergie though the same did not apply if you wear orange? Or maybe she was just especially proud of her matching bra and knickers?
Instead the gaps in the lace exposed her Bridget Jones-style pants.
But the singer was far from the only one to turn heads for all the wrong reasons last night.
Nicki Minaj's Grammys 2011 head-to-toe leopard-print ensemble was always going to be hard to top. But she left it in the shade last night, by turning up to the Grammys with the ultimate accessory... the Pope.
Lady Gaga - who dressed as a nebula last year and arrived encased in an egg the year before - almost seemed to have toned down her outfit for this year's awards.
She did not show off her dress on the red carpet, instead slipping through the back door into the Staples Centre in Los Angeles.
But indoors the Born This Way singer revealed a sequin-encrusted black gown with structured elements on the shoulders and torso as well as a gold a black walking stick.
It's the kind of dress we could imagine being worn by a host of stars - which by Lady Gaga's standards makes it seem positively unoriginal.
Cyndi Lauper also opted for a black outfit which showed a lot of leg.
Her triple-breasted jacket, with gold chains hanging off the shoulder and hip revealed a lacy camisole. And the Girls Just Wanna Have Fun singer's black and white head of hair did nothing to compliment the look.
Others who, perhaps have yet to make their mark on the music industry, used the Grammys as an excuse to draw attention to themselves.
Maroon 5 singer Adam Levine's girlfriend, model Anne V, showed off a lot of leg with a LBD that was split to the waist.
Jersey Shore's Snooki wore a black and white optical illusion style dress - paired with white high heels - that were not nearly glamorous enough for a red carpet ceremony.
The worst-dressed singer you've never heard of category was won by Nadeea, whose outfit would not have looked out of place on Dancing On Ice.