Reshammiya has refused to divulge any details but says it would be out before Eid (July 29).
"I can't reveal what surprise is in store for you but I can promise you that there is a great surprise from Salman bhai to all his fans and you all will love it. But at the moment it is very difficult for me to say anything," the composer said here Friday at the 75th birth celebrations of legendary composer Rahul Dev Burman, fondly called Pancham Da.
"But definitely before Eid you all will get a very big musical surprise from Salman bhai and you all will be more than happy," he added.
Reshammiya has composed the music for Salman's new film "Kick" and the two are now working on a song reportedly sung by Salman.