Christina Aguilera Dedicates Song to Fiancé Matthew Rutler As They Prepare to Celebrate Summer Rain's Birthday

Christina Aguilera dedicated a song to her fiancé Matthew Rutler Saturday night as they celebrate the first birthday of their daughter Summer Rain.

The 34-year-old star held a crowd of Hollywood superstars, potential U.S. Presidents and industry big-wigs spellbound as she performed at the hot-ticket event of the evening – Apollo in the Hamptons.

Christina Aguilera: 5 Times She Was a Body Image Winner

Christina Aguilera brought the heat to Instagram this week when she posted a topless selfie.

The Voice judge, 34, told followers that with her “it’s all real, all the time,” adding that she “felt like it was time to start sharing some personal stuff with you guys.”

Christina Aguilera Sizzles in Topless Instagram Photo: I 'Felt Like It Was Time to Start Sharing Personal Stuff'

Christina Aguilera is taking “up close and personal” to a whole other level in her latest Instagram pic.

Wearing nothing but pink underwear and a hat, the 34-year-old is seen in the mirror-selfie using only her arms to cover her chest. She has one message: “Just so you know with me, it’s all real, all the time.”

“Felt like it was time to start sharing some personal stuff with you guys And it’s just the beginning. Night night. X,” Aguilera captioned the photo.

Sawyer Fredericks Wins The Voice Season 8

Watch Christina Aguilera Impersonate Miley Cyrus, Britney Spears, Cher and More

Christina Aguilera has built her entire career on her voice. However, hitting high notes isn’t her only vocal superpower.

Listen to Christina Aguilera's New Song from the Finding Neverland Soundtrack

Christina Aguilera’s got new music, and it’s beautiful.

The Voice pro recorded a cover of “Anywhere but Here” for the Finding Neverland soundtrack, and with its soaring melody, it fits right in with Aguilera’s catalog of emotional ballads.

The Voice Finale: Who Will Win?

After a season full of steals, saves and tears, we have come down to The Voice’s final four – and it’s quite a bunch!

Because it’s impossible to decide our favorite finalist, PEOPLE has broken down and analyzed the final four in depth.

WATCH: Stephen Merchant Gets 'Dirrty' on Lip Sync Battle

This week’s Lip Sync Battle isn’t going to be a clean fight.

At least, not if Stephen Merchant has anything to do with it. In a clip from the upcoming episode, he channels his best “Dirrty”-era Christina Aguilera in an attempt to out-lip-sync opponent Malin Akerman.

Nashville Sneak Peek: Christina Aguilera's Jade St. John Gets Hot and Heavy with Luke (VIDEO)