I am a little confused, and I have never heard of anything like this nor have I seen it discussed anywhere. Search revealed nothing. I was at a rehearsal yesterday. So, I am playing my walking bass lines, and someone commented about how I need to stay out of the range of the pianist and the horn player, not go "up" when they ascend their notes. Not play up on the neck ,i.e near or at thumb position, when the trumpet player is playing in the upper range. Sorry, I have never heard of monitoring my walking lines like this when others are doing their solos. Have I missed a major piece of information? I think its really nice, for example, when the bassist mirrors the up and down movement when another instrument plays the head of a bossa, for example, but in walking during a solo? I think there's things I do intuitively to follow what the soloist is doing, but not necessarily being constrained in where I play on the neck or being mindful of not stepping on anyone's toe's so to speak. Confused.