That chart's not exactly accurate for guitar. E2 to E5 only gets you as far as the 12th fret on top E. As any electric player knows, the chances of frets 13 to N (where N is 20-24 depending on instrument) never being used is pretty damn low! :-)
I presume you're just using this to set up the default options? Better make it user-tweakable so that it's possible to play chords at the 12th fret...