Copyright On Musical Performances and DVD Recordings

Hi - I've been asked to perform as part of an musical ensemble for a commercial DVD. The material we will be playing are ancient sanskrit chants w/ a melody originally written/recorded by another artist. I have 2 concerns:

1. I'm not aware of any written release from the artist that wrote the melody. If I'm involved in this project as a performer & receive no renumeration (I'm doing it for the exposure) am I personally liable for copyright infringement even though I'm not the one selling the DVD's?

2. Is there such a thing as a copyright on the performance (digital/video recording of the performance) itself? Can we limit the use of this performance?

Thanks for any responses :D

I have never heard of a case where a copyright holder pursued a performer for copyright violation, where the performer had nothing to do with trying to distribute and/or profit from the work.

You can limit the use of a derivative work (a work dependent on somebody else's copyrighted material), as you hold copyright to your original contributions (but not to the original work).