Using copyrighted material - legal?

Hello. I would like to use a few clips from movies and other sources that may be copyrighted to make an album that I want to give away for FREE. But I also want to ask the listeners who enjoy it for a small monetary contribution to fund my future projects (and pay the original copyright holders if I market the album in the future). Being that payment will not be required and I will only be using clips no longer than 30 seconds (on the extreme but just to make sure), would that be legal?