Guitarist's "The Fretboard Rosetta Stone"

Guitars-Above Jason Isbell playing a Gibson Les Paul at ACL Live August 7th 2021 (RM2244.COM Archive). Like Segovia , I am guessing that Jason would concur, that guitar is on one hand the easiest instrument to start but the hardest to master. Unlike Piano, which with 88 keys each a unique tone on the bass and treble clef, guitar is organized in a way that many specific tones can be played on as many as six different locations on the fretboard. Ron Christie below posted an "ingenious tool" for understanding this for the treble clef. This tool is helpful to transcribe music notes not tabulated for guitar and also for converting tab to notes for other instruments.