Teaching an older person. they can’t exactly coordinate hands together the last 3 weeks. Now I’m thinking help lies (as always) in further simplifying the movement and reconsidering how they are thinking (or rather, how they are not thinking). sometimes the solution is realizing how the brain has limited itself to one solution and keeps repeating the same sequence with the same errors. just practising doing it wrong hoping it will correct itself. A better, or quicker outcome, lies in bumping the brain to think differently. In this case, they are experiencing lack of coordination and so we slow it down, so slow that we can notice other aspects of the experience which can’t be processed at faster speeds. Now we can observe the math. When your left hand plays those two notes together, simultaneously your right hand plays Eflat (etc.). That isn’t what they were previously doing. It’s a new angle for the mind, like slowing down a dancer and discussing how to do each step, when your left foot goes there your right hand goes there.