Mumbai, December 7: As filmmaker Karan Johar will be a part of a music reality show as a judge, the multitalented Bollywood personality said he cannot sing, but has a good ear for music."I have zero knowledge in singing. But I must mention that I have been listening to Hindi film music for last 40 years. So I have a good ear for music," Karan said during the launch of the show "Dil Hai Hindustani"."I have grown up listening to music. Even though I won t be able to find out technical flaws in any of the participants, I will be looking for the X factor," he said.Karan added: "I will be discussing with my other judges before taking any final decision on participants as people like Badshah, Shekhar (Ravjiani) and Shalmali (Kholgade) are music professional and highly educated in music."The show will air on Star Plus where singers from across the globe will participate.What makes the show stand out from any regular reality shows is that the participants can sing not only solo, but also duet and can give group performances consisting of bands, choirs, acapella that will open up the variety of genres and celebration of world music.Apart from Karan, singer Shalmali Kholgade, music director Shekhar Ravjiani and popular rapper Badshah will judge the participants.Karan, who has helmed films like "Student Of The Year" and "My Name Is Khan", says he appreciates when "new singers" upload their music on digital platforms."I really appreciate when new singers upload their music on YouTube and other such platforms. It always fascinates me to know that so much talent exists in our country. When I listen to those viral sensations (web stars) I feel amazed!"Adding to that rapper Badshah said: "Well, I was a web sensation and now I am judging the show. So you can understand the impact of digital media.""It would be very easy to impress me so I won t be a tough judge. But they have to impress the other judges also," Badshah said.Emphasising on the show s concept, Ravjiani said: "Dil Hai Hindustani is one of the most exciting concepts I have come across on small screen. Judging a talent show is not a new phenomenon for me but the idea of putting performance over talent will be very interesting for us."