When you are soloing, what is the relationship that you expect as a bass soloist from the comper? Can you describe how you interact with the comper? What do you want from them, as a player? I'd like to hear lots of different perspectives as I doubt if it's the same for everyone.
Wow great question Huy,
+1000 to what Paul stated;
I like players who listen real hard, are conversational, can suggest alternate harmonic ideas that can push you farther in the direction that you're going and of course have a strong sense of time so they don't have to play downbeats to mark where they think we are in the tune. Drives me crazy when whoever is comping rushes and/or dictates through increased volume or basic chord choices where they think my solo is going!

