Mariah Carey 'Emotions' Ride High at Star-Studded Person of the Year Event!!!

Grammys weekend kicked off by honoring the most iconic diva of them all -- the one and only Mariah Carey!

The singer-songwriter was shining on the red carpet at Friday's MusiCares Person of the Year Gala in Los Angeles ... commanding attention in a sheer floral dress with a corseted bodice.

She layered on the bling with a diamond collar necklace, stacked diamond bracelets and waterfall diamond earrings ... though no jewelry could shine as bright as her A-list smile.

Plenty of stars showed up to support Mariah as she was awarded the Person of the Year honor ... with the likes of Kesha, Dove Cameron, and Charlie Puth infusing the affair with a little extra star power.

Inside the signature Grammy event, myriad musicians took the stage to honor the "Obsessed" hitmaker ... including Jennifer Hudson, who gave her all while belting out MC's hit track "My All."

Taylor Momsen and the Foo Fighters opted for alt-rock instead of pop ... reminding everyone Mariah went through a secret rock star phase with the band Chick in the 1990s!

While performances kept the energy high, none of them could match the moment everyone was waiting for ... Mariah's acceptance speech -- where she thanked a ton of people and called the outpouring of love "overwhelming."

Mariah's not up for a Grammy at the awards on Sunday ... but, we'd say she's already won the weekend!