netmeg - 4:32 pm on May 25, 2012 (gmt 0)
Typically the highest paying ad unit is the first one on your site. You can also use section targeting to try to convince AdSense what to base the contextual ads on. But if it's significantly different than the focus of your site, it won't work.
Bottom line is, you are in a niche that typically will never pay really well unless you get gobs of traffic. Believe me, I know; I've been connected to the music biz for well over twenty years. Advertisers will block band/fan sites (unless they are specifically trying to target them, and very few high paying ads are trying to target them.)
Set up a section to talk about guitars, amps and whatnot, and you might do a bit better.