Monday's episode of "The Voice" US season 9 will feature the first part of the Battle Rounds that will see a select few advancing to the next level of the competition.

Episode 7 of "The Voice" season 9 can be watched live on NBC at 8 p.m. ET. A livestream of the first Battle Rounds is also available on NBC.com, provided the viewer has a subscription with a participating television provider. The episode can be watched online for free the next day on NBC.com.

The seventh episode of the season will see each of the coaches – Blake Shelton, Gwen Stefani, Pharrell Williams and Adam Levine – bringing celebrity mentors to help the contestants. This year's celebrity mentors include John Fogerty (Team Adam), Brad Paisley (Team Blake), Selena Gomez (Team Gwen), and Missy Elliott (Team Pharrell).

Speaking of her stint on the show, Gomez said "The Voice" gave her the perfect platform to teach as well as to learn.

"I'm learning a lot being here. I've been in a transition period with my music, so it is, like [Gwen] said, inspiring," Gomez told Access Hollywood in an earlier interview. "I love being in the presence of women, especially women who are so comfortable in their own skin and support other women," she added.

Pharrell, in the meantime, raved about his celebrity mentor saying Elliott's presence will force his contestants to challenge themselves.

"She is unbelievable," Pharrell told reporters during a "The Voice" event. "Because of her, I feel like my artists will challenge themselves to be more open and less categorical. They will be less classifiable, live in the moment and exercise creative license whenever they want. That's what she is. That's what Missy does. She liberates people."

"The Voice" is aired Mondays and Tuesdays on NBC.