To get a read

I need to learn how to get a better read on people. I've got a bit of a conundrum. I should know better by now, though. For about 20 years now (I was very very very young!), I've been around a lot of musicians, actors, dancers, artists. I thought I had developed a good read on people, primarily artistic people. See, the thing about them is that while some a generally nice, warm, outgoing people, others are just pleasant enough to get you to come to their show/expo/whatever. I had been very good at separating the wheat from the chafe on this topic. Case in point, my very very good friend JB. I consider him my best guy friend. We've been friends for 17 years. In those 17 years he has been in many many bands. He's currently in three or four - I can't keep up. I do go to his shows when I can, because I enjoy the music, and his band mates are awesome and I like hanging out with them. JB is my friend, really and truly. Supporting his music is something I do, not something he expects of me. That being said. I have some other people around, acquaintances more than friends, that I can't get a good read on. They are mostly musicians and dancers. The problem could be that they have been artists for so long, that maybe they don't even know whether they are trolling for ticket sales or being open and friendly. I don't know how to figure it out. This is not a huge thing, just something that's been bouncing around my brain for a while.