Yuvan Shankar Raja singing the song Kaatrukulle from Sarvam. In the background, they released what appeared to be floating jellyfish.

Yuvan Live @ KLIMF 2012 concert was held on 15 December 2012 at Bukit Jalil, Kuala Lumpur.

Additional info:

Yuvan Shankar Raja is a Tamil film score and soundtrack composer, singer and occasional lyricist. He is the third and youngest child of musician and film composer Ilaiyaraaja.
http://en.wikipedia.org/wiki/Yuvan_Shankar_Raja