Raja Hasan has recorded two songs with Bappa Lehiri for the film, FLAT. One song is a duet with Sunidhi Chauhan. The other is just a small part with Sonu Nigam.
Raja Hasan has also recorded two songs with Amit Trivedi. The name of the films are not yet know.
News is that Raja Hasan has also received a call from Pritam Chakraborty and would soon be recording a song with him too.