Mathematically speaking, the guitar fingerboard is simply not one-dimensional like the piano, and attempts to render it into a one-dimensional form, such as standard musical notation, is necessarily going to cause ambiguities and distortions, and dramatically interfere with the player's ability to sight read. (Map projections that attempt to depict the earth on a piece of paper also force dimensional distortions, as we all know.) A 2-dimensional piece of paper can show a reasonably good represenation of one-dimensional keyboard graphed against time. It is clear to me that guitar players will not be able to sight-read as well as keyboard players until a 3-dimensional notation is developed. This would then show how the 2-dimensional guitar fingerboard behaves when graphed against time. Instead of a note with a stem on it showing its duration, there would need to be something like a guitar chord grid with a flag or a stem. It may be that computers will allow us to do this, and it may need to actually be a movie-like thing, and I encourage exploration of this idea. And even if it is developed, I have no illusions that it will come to be adopted any time into our present system of music education and performance, and guitarists will have to remain philosophical and put up with the way it is.