Megastar Amitabh Bachchan is spending his free time composing music.

"I have been busy with yes, music. And once it starts it's a different world. Singing, composing, arranging and providing instrumentation all by myself can be arduous, but so fulfilling, " Amitabh tweeted.

The 69-year-old has been off work for sometime after undergoing abdominal surgery last month. Although the actor says he is recovering well, he is still in pain.

"All is well... I repair well, and gradually... but had to miss gym... urgh ! hate it when that happens... one surgical pain reappeared !" he said.