"What is professionalism?"
- There are a lot of elements. Show up on time, do what you agreed to ect. and the other side is standards of quality. Some restaraunts have a dress code, and won't serve certain things.
Some musicians have specific parameters they have held to.
Another thing is, you can look at my bio see I have worked with a fair amount of names, mostly in free jazz, but folks who have made their name. I have also done organizing for a lot more players than I played with. The one thing that seems to get to name players is just not respecting or being aware of their work.
Most artists have ideologies, whether or not you guys believe or respect that, it is true. So you can't put together a concert with Anthony Braxton's compositions with an improvisor, say Derek Bailey when he was alive, who is ideologically opposed to composition.
When I organize concerts go over all the details, venue, other musicians, what they do, what they don't do, amplifacation, etc. Very often these conditions are much more important than the fee.
Professionalism in this case would be to have an understanding of Peacock's artisic parameters before hiring him.
"Where do we (each) draw the line when the expectations at a gig get changed?"
-Just personally I won't play current pop music ever, or any written material without prior negotiation, with too loud a drummer, or with someone who is not interacting. I also won't rehearse unless there is a fee for it or it is with friends or a master player.
In general I like to play in places where the audience sits and listens and there is no noise made by anyone but the musicians. I much prefer that to a good fee, or big audience. Since I tend to get it, I see the other situations as a fun challenge once and while.
"Is our perception of a certain artist changed when we know a bit more about his attitude and personality?"
-I think it depends on the next question. If I like their work generally no. Braxton got in a fight with Peter Kowald because Braxton loved Wagner, Kowald said he shouldn't since Wagner was Facist, Braxton said the history of music is not the history of nice guys.
That is true, often a being great player means a lot of time spent alone in a room with an instrument, there are many things that can drive a person to that, not all of them positive.
One thing I love about jazz and improvised music is you can work with really quirky personalities, since you just meet at the gig and part ways after. Of course the hang is nice, but not always nesssary for making good music.
"Are there 'levels' of art?"
Yes, but they are personal, and based on each persons core values.
Clearly a lot of people hold EC high regard, personally I find him dull and bland, but not offensive. I respect hard work, commitment to music for music sake and innovation. Others have different parameters altogether.