Composer Devi Sri Prasad has made an absolutely iconic tune for this song - with only 4 notes!
Every line in this hypnotic "item song" has the same tune, but it doesn't bore us. It is intriguing. How did they do that? Watch!

A couple of exceptions:
At the very end a couple of words get a higher pitched note. The words "Oo oo" and "mama" go higher than the 4th note. But it's just for emphasis, and can be neglected, because the same lyrics have stayed within the 4 notes in other places.