I know I'm going to sound like a geek here, but I have really been enjoying learning some new music theory lately. I guess it's really applying it that's fun, though. I've been spending a lot of time on the circle of Fifths and have tried relating each key in the circle with its scale and with its relative minor, going through the scales and through the relative minor scales. This has become a jumping off spot to finally kind of understanding the structure of the songs we've been playing. It's also helping a little with doing solos, although I still am struggling with some of the tunes. But I never expected to be this interested in this stuff or to be able to actually apply it.
I can't relate music theory to algebra, but the more theory I learn(and understand) the easier it is to apply it to my everyday practice and playing. It will help you over the rough spots and make sense out of the senseless.