MUMBAI: Coldplay frontman Chris Martin has been signed onto NBC's singing competition 'The Voice' to help the show's contestants. The singer will play adviser to the show's four coaches- Shakira, Usher, Adam Levine and Blake Shelton. According to reports, he will make his first appearance when the show enters its second phase- the Battles Round, and on two following episodes.

Speaking about the new appointment, executive producer for 'The Voice' Mark Burnett said, "He's such an authentic voice in the industry. We could not be happier. There's a massive level of respect from the singers and the surprise from them (when they met him) : 'Whoa! Chris Martin. Wow!''

Instead of making the announcement on the show itself, 'The Voice' took to social media to reveal Martin's involvement. After Tuesday's broadcast of the show, footage of the 37 year old singer was released through the popular app Snapchat. Prior to the revelation, fans were alerted about the announcement through various social networking sites like Facebook, Twitter and Instagram.

The 'Battles: Round two' phase will see a change in format. Unlike the previous format which saw two contestants performing a song of their choice in a knockout stage, the new one will see contestants paired up, but separately perform the same track in a sudden death round.

Martin is the latest of several big names offering his expertise to the show's contestants. Current mentors for 'The Voice' include The Band Perry, Miranda Lambert, Aloe Blacc and Jill Scott.