They may be big names in the Bollywood music industry, but music director duo Vishal-Shekhar did not shy away from asking music maestro A.R. Rahman for his autograph.

They met Rahman on the sets of Zee TV's "Sa Re Ga Ma Pa Singing Superstar" -- the music maestro came with actor John Abraham to promote their upcoming project "Jhootha Hi Sahi".

Vishal was especially enthusiastic about his first meeting with the Oscar winner and urged Rahman for an autograph, said a source from the sets.

On meeting Rahman, Vishal said: "Each decade in the Indian music industry has an identity - the melodious 60s, the swinging 70s, disco of the 80s and the 90s was a one man show - A.R. Rahman who pioneered a distinct phase in Indian film music combining western influences with Indian sounds, ranging from classical instruments to folk music."

Vishal even asked Rahman to sing the latter's version of "Vande Mataram". But Rahman couldn't fulfill his wish.

"I will not be able to do justice to our national song today because it needs to be sung in a high pitch, and it will be difficult for me to summon that amount of energy on an empty stomach. It's the holy month of Ramzaan and I am fasting, " Rahman said on the day of the shoot, Sep 7.

The special episode of the music reality show will be on air Friday.