Getting back to Mike's comment, I've seen a number of jazz bands where the drummer is on the front line, to one side, with the drums angled around to where everyone can see each other. I have a vague recollection of seeing Return to Forever in the seventies where the keys and drums were close to the edge of the stage at either end pretty much facing each other, and the bass and guitar stood back away from the front of the stage so that they formed a semi-circle. I like that setup a lot. Everybody can easily see everybody else.