Considering that it’s viewed as stealing (even when you make a mixtape for friends), I can only imagine that it would be the same when you go to sell one for charity. I work in the music/entertainment field, and almost every CD that passes through my hands has a “please don’t copy or lend to others to copy” message on it. If even YouTube requires artist’s or label’s permission to use music in a video on their site, I would assume your situation is similar. One solution might be to bring up your idea to the person at the synagogue in charge of rounding up donations for the charity auction. See if they are comfortable with your idea, or if the religious community there would be OK with auctioning off a CD that is a copyright infringement. Lastly, one way you could still do this legally is to make a playlist with your chosen songs on iTunes, and donate a gift card that you bought to be auctioned off. The winner could then purchase your mix with the gift card, or other music if they want. Hope it goes well! :) And good on you for wanting to contribute to your auction’s success. That sounds like a very worthy thing to do.