Lizzo, Billie Eilish and Lil Nas X are ready to make a splash at Sunday's star-studded Grammy awards, where pop's new guard is poised to win big -- even as scandal backstage has threatened to tarnish the glitz.

Music's marquee night in Los Angeles promises to deliver rollicking performances from the zeitgeist-capturing newbies, as well as tributes to the veteran rockers Aerosmith and the late rapper Nipsey Hussle.

But even as the glamorous show aims to reinvent itself with an injection of youth, while also spotlighting women and promoting diversity within its ranks, controversy is simmering.

Just days before the gala, the Recording Academy's suspended CEO Deborah Dugan -- the first woman to lead the embattled institution behind the Grammys -- filed an explosive discrimination complaint with the Equal Employment Opportunity Commission.

She says she was suspended after raising concerns over sexual harassment, voting irregularities and other misconduct within the Academy -- one of music's most influential organizations, but one long accused of favoritism and a lack of diversity.

Dugan also alleged that her predecessor, Neil Portnow, had raped a foreign female musician -- an allegation he has rejected as "ludicrous and untrue."

The storm has threatened to cloud the Grammy celebration, despite a diverse slate of nominees that celebrates a mix of established and budding stars.

"The timing of it is a shame and the whole situation, it's a shame," said Michael McDonald, the chair emeritus of MusiCares, the Academy's charity arm that supports music industry members. "I think it's really important that we focus on the positives," he told AFP on the red carpet at the annual MusiCares gala on Friday, which this year honored Aerosmith.

Still, McDonald said the Academy must take a long hard look at itself and at reform: "Things have to evolve."

The magnetic Lizzo, 31, is poised to be this year's queen bee, leading the Grammy pack with eight nominations, including in all the top four categories (album, record and song of the year plus best new artist).

The 18-year-old goth-leaning pop iconoclast Billie Eilish and the overnight country-rap sensation Lil Nas X, 20, both have six chances at Grammy gold, while the enigmatic 22-year-old R&B prodigy H.E.R. has five.

The establishment's newcomers will square off against veteran powerhouses including Ariana Grande and Beyonce, as well as alt-leaning acts Lana Del Rey, Bon Iver and Vampire Weekend.

The shift follows years of sharp critique from top-tier artists including Frank Ocean, Drake and Jay-Z, who have all slammed the Grammys as irrelevant, especially citing its failure to recognize black artists.

Though one-time Grammy darling Taylor Swift is up for several awards including Song of the Year, many mainstay artists are not "looming significantly" over the ceremony as they have in years past, Lehigh University professor John Vilanova, who has researched the intersection of race and gender at the Grammys, told AFP.

"They aren't leading the discourse, they're afterthoughts -- and when has Taylor Swift been an afterthought?"

Often remembered as much for its performances as its winners, the Grammys will feature Lizzo, Eilish and Grande, along with a genre-blending rendition of Lil Nas X's mega-hit "Old Town Road" that will feature K-pop sensation BTS, country star Billy Ray Cyrus and the eclectic DJ Diplo, among others.

Artists including John Legend, Meek Mill and DJ Khaled -- all up for Grammys this year -- will perform a tribute to the late rapper Nipsey Hussle, who was shot dead last year and is up for three posthumous awards.

The British country-soul revivalist Yola, up for four Grammys including the prestigious best new artist prize, said she's still soaking in all the glamour.

Upon learning of her nominations, the bluesy singer with a big voice told AFP on the MusiCares red carpet that she "cried for days."

"It was hilarious and emotional and I'm just so thrilled to be here," she said.