Billie Joe Armstrong a new ‘Voice’ mentor

Billie Joe Armstrong sits with Christina Aguilera.

LOS ANGELES — NBC’s “The Voice” is adding a high-powered rocker to the mix.

NBC says Green Day vocalist and guitarist Billie Joe Armstrong joined the talent contest as a mentor to Christina Aguilera’s team for this coming season.

In a statement, Armstrong said he and his family are fans of the show. “The Voice” has won over viewers because “it’s not molding artists, it’s just giving them a little bit of guidance and direction without giving them a complete makeover,” he said.

Besides, Armstrong says, working with Aguilera is “a lot of fun.” He started taping Wednesday on “The Voice,” which has been in production for season three since June.

As the talent contest field grows more crowded, shows are competing for big-name music stars. “American Idol” is adding Mariah Carey as a judge, and “The X Factor” signed Britney Spears and Demi Lovato.

“The Voice” returns Sept. 10.

In addition to Aguilera, the show’s coaches include Cee-Lo Green, Adam Levine and Blake Shelton.