The singing reality competition show landscape is pretty crowded these days.  The battle is getting ready to heat up between NBC and Fox with The Voice and The X Factor both making their fall debut the week of September 10th.

Each show has created a celebrity panel and have added additional celebrities to mentor.  NBC's The Voice judging panel consists of Adam Lavine, Cee Lo Green, Christina Aguilera and Blake Shelton with Rob Thomas, Billy Joe Armstrong, Mary J. Blige and Michael Buble serving as mentors with the vocal coaches.

The X Factor has added two new judges to the panel this year to accompany Simon Cowell and L.A. Reid.  Britney Spears and Demi Lovato round out the four judge panel.  Yesterday, it was announced that Nick Jonas would be serving as a mentor to the contestants and now it's being reported that Justin Bieber will be doing the same for The X Factor.

It's worth noting too that these aren't the only singing competition shows on the TV this fall, the CW has their show called The Next which features Joe Jonas on the judging panel along with Gloria Estefan, John Rich and Nelly.

NBC has released a new promo for The Voice in which the judges poke fun at each other.  Check it out!