Reba McEntire and Monica

NBC's new singing competition The Voice is adding more star power to its already super-charged panel of judges. Reba McEntire, Monica, Sia and Adam Blackstone have joined the show as "industry insiders" who will help mentor the contestants alongside the coaches, the network announced Friday. 

Coaches Christina Aguilera, Adam Levine, Cee Lo Green and Blake Shelton chose their advisers to help them with the next round of the competition, dubbed the "Battles" phase. Contestants on the same team will go head-to-head and their coach chooses the victor.

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Aguilera will team with singer/songwriter Sia; Levine will work with Maroon 5 music director Blackstone; Green has chosen Monica, best known for her album "The Boy Is Mine"; and Shelton has country legend McEntire.

The series, which debuted to 11.8 million viewers, will air at 9/8c this Tuesday before moving to its regular 10/9c timeslot on May 10.