(InStyle) -- Music's biggest night has always been known for over-the-top style, and this year's crop of Grammy nominees -- from Taylor Swift and Lady Gaga to Katy Perry and Beyonce -- are some of the most fashion-forward yet.
But the best-dressed stars on Sunday evening will strike that tricky balance between cool and killer, opting for looks that are unexpected, yet still gorgeous and elegant.
What does make for the right dress on the big night?
"Most award shows focus on movies and television, and the audience has come to expect stars to dress in a very prescribed way," explains InStyle's Fashion Director Hal Rubenstein. "However this is the music industry, and up until recently, glamour wasn't the main focus."
Artists wanted credibility: "The whole idea was to show up looking cool."
"The reason so many in the past stumbled sartorially at the Grammys is that they put on what ended up looking more like a costume," he says. "They weren't dressing down, they weren't dressing up -- they were dressing over."
But times have changed. This generation of singers really wants to look glamorous. "They're dress-up girls," says Rubenstein. And they'd do well to look to artists like Gwen Stefani and Rihanna, who were pitch-perfect over the past decade of Grammy red carpets.
Gwen Stefani is the master of making the unexpected appear chic. "She has a very unique look to start, a bit Marilyn Monroe in the '50s, and her unusual taste level weaves a blend of retro and modern," Rubenstein says.
InStyle's December cover girl Taylor Swift told us it was her dream to be dressed by top fashion designer Oscar de la Renta, which we made a reality.
"This is a girl who just got it right away. She loves to look pretty," says Rubinstein. "But most importantly, she hasn't let go of the fun of her age (20) and who she really is."
Jennifer Hudson may have been introduced to much of the country on American Idol but it was "Dreamgirls" that made her a star. "You're in 'Dreamgirls,' standing next to Beyoncé, so who better to take your cues from? And it sure worked -- she looked smashing in this red Cavalli."
Wearing dresses by designers like Zac Posen to cult favorites like Christopher Kane, Rihanna is a true fashion lover.
"It's not just that she can wear almost anything. She's willing to take chances, even changing her haircut once a week if she has to," Rubenstein states. Her dedication to being unpredictable has truly paid off for the trend-setting superstar.
Katy Perry has had all eyes on her since her blockbuster single, "Kissed A Girl." While she's had as many fashion misses as hits, we think this feathery Jenny Packham mini sounded all the right notes.
One person who rarely misses is the reigning queen of the music red carpet: Beyoncé. Says Rubenstein, "She's got that glorious face, that radiant smile, and those curves! We love that she enjoys showing them all off."
While Adele may seem an unlikely choice, "we're inspired by people who may be a little bit off mainstream, who go out there and make choices that are exactly right for them. The result is even more interesting," says Rubenstein.
Lady Gaga is sure to surprise on Sunday night (why pretend we have any clue what's up her red lace sleeve), but will anyone knock one of these ladies off the best-dressed list? That remains to be seen, but we're sure the red carpet is going to be a glamorous sight to behold.
Don't miss the Grammy's top fashion moments with our live coverage, starting on InStyle.com at 6:45 p.m. EST, Sunday, January 31.