One of the coolest things I saw at Linda Burkhart's and Gayle Porter's workshop at the ISAAC conference was the Yes Song and No Song Gayle's school uses to teach yes and no. As far as I can find the song isn't available anywhere on the internet. However some other songs are. Another option is to work with your music teacher or music therapist to create a song. This might be especially vital if you work with students over preschool as the selection of songs below is not age appropriate. (With the exception of the Beatles!)
It is vital to model the way you want your students to communicate yes and no throughout the songs. Perhaps a turn for each child with specific modeling of their way of communicating yes and no.
Remember you can download the music from videos using this site.
The Yes No Please Thank You Song
Uh huh, Uh huh, Ut uh
Wild Bear Yes or No Song on LastFM