Of the people you have played with through the years, what qualities separate the best people to play and create music with?

interactive listening.......folks that play with open ears and are trying to serve the music rather than show off.......people with proper time who create no pointless personal drama. 

Hey DadddyRay ... yeah, interactive listening is an important one from my perspective too.  

I use to play with a group of guys a couple years back and it was always cool during a jam when someone introduced an idea and the others built on it ... the real time creative process was just so exciting.  Totally immersive and joyful.

The point about listening to each other is crucial. Often, beginners are so wrapped up in their own performance that they don't listen to what's going on around them. You have to have one ear cocked to what the other guys are playing and, ideally, you play off of each other and if you like a riff or line that someone plays you might take that and put your own spin on it. It should be a mutually involving and evolving conversation.

I think the best bandmate shows up on time, listens to the music and knows how to share with and support the other players.

@Jerry .. yes, you're exactly right about beginners and even intermediates.  I struggled with exactly the issue you mention ... i.e. being able to free my mind from my own playing enough to truly listen and respond to others.  

I bet this wraps back to your earlier points on how one learns to play music ... i.e. if you're focused on the music you hear your bandmates playing ... and your own ideas / intentions in your mind ... and have the muscle memory to push it out, it's easier to play generously with people and really create somthing.

@Corey .. very true. It's similar to creating software and other complex creative tasks.  If you have someone on your team (or band) that makes everyone 25% better ... it can be as important as having a star individual.  Although I haven't read much about it, I imagine Duke Ellington must have been this way.  The talent he assembled through the years was incredible ... so he must have been able to create a band where people felt they could bring forth their best music.

I always say that the cat who is consistent, easy to work with, mature and on time will beat the prima-donna musician who may play better but who is always late, immature, diffifuclt to work with.  Music is a business like any other...it requires team players.