SHANKAR VS AR RAHMAN VS RFAK VS PRITAM

WHOM DO U THINK IS BETTER IN SHANKAR MAHADEVAN,AR RAHMAN,RFAK AND PRITAM?
I KNOW SHANKAR IS THE BEST WHEN CONSIDERED TO DEEP,VERSATILE AND HIGHEST PITCHED VOICE.
AR RAHMAN IS A WORLD REOWNED SINGER AND MUSIC COMPOSER
RFAK IS A TRADITONAL SUFI SINGER
AND
PRITAM HAS GIVEN SOME NICE WORKS LIKE DHOOM
PLEASE POST UR VIEW WHEN IT COMES TO CLASSICAL SONGING
TRU TO SEE SHANKAR MAHADEVAN MITWA SONG IN MKMM PREFINALE

All are very good and they are better known as Music Directors, all can sing well but Shankar ji is a classical singer too.