Gal Mitthi Mitthi is a Punjabi song from Aisha, compose by Amit Trivedi and penned by Javed Akhtar. The song is a dance number in a Happy mood.
Gal Mitthi Mitthi bol means talk sweet things and the next line ras kaano wich ghol means say sugary sweet liquid in my ears. Bajne de taashe dhol simply means let the drums play, or as we can say, let the music play.
A likeable song.
Update: Here is the meaning of the complete song.