Thanks for clarifying, Lox.

The sort of factors to which I was referring are the details normally associated with the emotional content of the music - much of which is provided intuitively and unconsciously by the player. The written page could never convey such subtleties with any guaranteed success of accuracy, and to me it would be an undesirable thing. Even to convey such things approximately requires skilled demonstration. A simple example of that would be the 'skank' in reggae music - dead easy to write down, but it at least needs to be heard to have any hope of creating the desired effect. The blues is another example; Josepp reckons he learned blues from a book. I think not, and that's without even hearing him try. There are elements in music which are far too subtle for verbal description or graphical representation. That's what teachers are really for - the rest can be found in books. Blues, like reggae or jazz or folk or soul or [whatever], is a feel and an attitude. Without that the notes are just notes. Unfortunately there are people who can't tell the difference, albeit through no fault of their own, and it doesn't necessarily stop them appreciating other aspects of the music. It's all very subjective - that's why it's magic ;-)