Christina Aguilera Welcomes Gwen Stefani to 'The Voice'

She ain't no Hollaback Girl, but she's a new "Voice" coach. As rumored, Gwen Stefani will be joining the show's Season 7 panel, sitting in one of those big red chairs alongside her longtime friend and collaborator, Pharrell Williams.

Who confirmed this news? A source very close to the show: none other than on/off original "Voice" coach Christina Aguilera, who tweeted her congratulations to her temporary replacement on Monday evening. (UPDATE: Christina may have jumped the gun slightly, since NBC did not issue a press release officially announcing Gwen's hiring until late Tuesday, right before "The Voice's" top 10 live results show.)

Gwen will be filling in for Christina — who, by the time Season 7 starts taping in June, will be close to nine months pregnant — and for current Season 6 coach Shakira, who will be spending the summer touring to promote her new album. Christina is expected to return to the show for Season 8, which airs in spring 2015.

Now that Gwen is on board, it's time to list some reasons why she could be a hella good fit for "The Voice." Here's four:

She'll have chemistry with Pharrell. Gwen and Pharrell's relationship dates back to 2002, when his production team the Neptunes worked on No Doubt's "Hella Good" single. The Neptunes also produced her massive hit "Hollaback Girl," and Gwen guested on Pharrell's solo single "Can I Have It Like That?" in 2006. Pharrell and Gwen looked like they were having tons of fun together when they reunited onstage just two weeks ago at Coachella, so hopefully that easy chemistry will translate to the small screen.

The '90s are so hot right now. While Gwen has enjoyed a healthy career throughout the 2000s (her debut solo album came out in 2004), to many nostalgists, she will forever be "Just a Girl" in bindis and Dickies. Come on, with a '90s revival now in full swing, you know you want to hear Gwen sing a No Doubt medley — or maybe a duet with her totally-'90s husband, Bush's Gavin Rossdale — on one of Season 7's results shows. Make it happen, NBC.

She's a rock chick. Sadly, female rock singers never win shows like "The Voice." Juliet Simms came close in Season 2, but she ultimately placed second. Cassadee Pope, former frontwoman for Pete Wentz-associated emo band Hey Monday, pulled it off in Season 3, but only after she switched her allegiance to country music midway through her run. Kat Robichaud, the glitter-rock goddess who covered AWOL Nation and wore leather hotpants at all times, only made it to 10th place last season. But with someone like Gwen championing the cause, maybe a real rocker girl could finally reign supreme on "The Voice."

She's got some wicked style. Remember when CeeLo Green would appear on "The Voice" in an Elvis jumpsuit, Stormtrooper armor, or a Jheri-curled Prince wig? Or when Xtina would wear what looked like a sequined diaper, a "Dangerous Liaisons" costume, or a pillbox hat shaped like a vinyl 45? We all miss those days. So here's hoping Gwen rocks every bizarro L.A.M.B. get-up in her closet during Season 7. Heck, she can even bring back her pink-hair-and-orthodontia look from the "Return of Saturn" era, if she wants.

"The Voice" Season 7, with Gwen Stefani, Pharrell Williams,  Adam Levine, and Blake Shelton, airs this fall.

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