Gwen Stefani

Singer Gwen Stefani, performing with Pharrell Williams recently at Coachella, is joining NBC's "The Voice" as one of the coaches. (Christopher Polk / Getty Images for Coachella / April 11, 2014)

Singer Gwen Stefani is joining NBC's “The Voice” reality singing competition as a voice coach along with her friend and periodic musical collaborator Pharrell Williams for the seventh season of the show, joining longtime judges Adam Levine and Blake Shelton on the panel.

The No Doubt singer, chief songwriter, solo pop-rock star and fashion designer will give viewers a sneak peek at what’s to come in the fall season when she performs her hit single “Hollaback Girl” on Monday’s edition of the show. Williams is also scheduled to make an appearance to perform his new single, “Come Get It Bae.”

Stefani, 44, showed up as a guest recently during Williams’ performance at the Coachella Valley Music and Arts Festival and the pair performed “Hollaback Girl” together, a song she wrote with Williams and which he produced for her.

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Stefani’s participation on the show had been hotly rumored recently, and on Tuesday she tweeted a photo of her right hand clutching a microphone, her index and middle fingers up in the V sign above the words “it’s true … gx @NBCTheVoice.”

The in-progress sixth-season coaching team consists of Shelton, Levine, Shakira and Usher. NBC has announced that original-season coach Christina Aguilera will return to the fold for the show’s eighth season.

The combination of Stefani’s return to the pop spotlight at Coachella, joining “The Voice” and Aguilera’s return to the show down the line would appear to set the stage for another Stefani solo outing.

After her two hit solo albums — “Love. Angel. Music. Baby” in 2004 and “The Sweet Escape” in 2006” — she and the members of No Doubt released the new album “Push and Shove” that sold modestly and launched their first tour as a band in more than a decade.

During interviews in 2012, however, Stefani told reporters she never wanted to make another solo album.