I recently started to read Mick Goodrick's well-known book "The Advancing Guitarist", but I got stuck at the very beginning. The first chapter of the book talks about how playing on one string can improve some important, mostly unnoticed skills. However, at some point he suggests an exercise working on this concept: "Record suggested modal vamps on your tape recorder. Each modal vamp should be at least two but not more than four minutes in length. This way, all seven vamps should fit on one side of tape (30 minutes)."
Now, I got the whole idea he was trying to explain. But I am really curious, what exactly is a vamp? I know what "modal" supposed to mean as an adjective, but I couldn't really figure out what a vamp is. Is that a concept? a measure? or some kind of name to refer to a group of specific chords? I don't really know. Any help?
p.s: I'm a newbie here. So forgive me if this question considers a duplicate. I searched, but couldn't find anything.
