Paul, I don't think anything "comes natural", I think it "BEcomes natural" with enough practice. Bass lines are more natural to me but that's from years of playing jazz organ. Still, left hand comping on either piano or organ, feels pretty 'natural' to me because it not only provides the harmonic structure but (in the right hands) also contributes to the rhythmic feel. In a piano/bass/drum trio, it IS the 'rhythm guitar'. I tend to like the strong rhythmic players like Les McCann (who just happens to be a friend of our own Capt Russ - from same hometown). Great topic though, and certainly a weak area for a lot of keyboard players.

chas