I've been playing bass for around six months now after six months of guitar and a couple years of saxophone. I like to think that my understanding of chord shapes and functions is pretty decent, but I'm having a hard time with walking four to a bar. I've been working on Autumn Leaves and I can do the changes somewhat comfortably with a two feel (with roots, thirds, and chromatic approaches) but when I move to trying to do it in four, my brain and hands seem to forget what they're supposed to be doing. Should I take the tempo down? Learn to play it perfectly by memory in two and then move on to four?