No matter whether I record each track separately or together, what is recorded anew also includes whatever is on the other tracks. So, if I record vocal and guitar on separate tracks at the same time, they each contain a pretty good version of the other--that is, the vocal includes the guitar and the guitar includes the vocal. If I record only the guitar as the first track, that is fine (of course, there is nothing else in the file). But when I record the vocals, the guitar is recorded along with the vocals on the new track. If I record a third track, it also includes both the guitar and vocals. What I want is for each track to be as separate from the others as possible (that is, they contain no sound of the other tracks at all).