I am learning bass guitar and just want to make sure i am using my thumb anchor properly , I have a 4 string bass and use the side of the pickup cover and the E string and A string as thumb rests , Lets say i have open notes E - E - A - E- E to be played , Starting off with my thumb on the pickup cover playing open E - E should i then stay on the pickup cover to play the open A string or should i rest my thumb on the E string to play open A .