Not at all, that isn't a derail. Those are legitimate questions.
Well, buying the circle's material, for starters, helps. Let's assume this is already done.
You could conceivably contact the circle and ask for their permission to upload one of their songs onto YouTube with an accompanying image. But then ask, what is your motivation behind wanting to upload the song? To share it with friends, you could literally share it with your friends via email. To share it with the rest of the world, you could post a link to the circle's site (most of them will have audio samples, usually one track of 20-second samples of each song on an album crossfading into each other) on your social network of choice. And of course you could go on and on to anyone who will listen about how awesome Circle X's latest album is. Follow them on Twitter - a lot of them will livestream on Ustream now and then. When this happens, link to it so others can witness them in their live glory.
I mean I get that you want other people to hear how incredible This Song is. I love sharing music that moves me. There's just a lot of different ways to do it that go beyond straight up uploading the whole song to YouTube.