The electric guitar, developed for popular music in the United States in the 1930s, usually has a solid, nonresonant body. The sound of its strings is both amplified and manipulated electronically by the performer. American musician and inventor Les Paul developed prototypes for the solidbody electric guitar and popularized the instrument beginning in the 1940s.
On almost all modern electric guitars, the bridge has saddles that are adjustable for each string so that intonation stays correct up and down the neck. If the open string is in tune, but sharp or flat when frets are pressed, the bridge saddle position can be adjusted with a screwdriver or hex key to remedy the problem. In general, flat notes are corrected by moving the saddle forward and sharp notes by moving it backwards. On an instrument correctly adjusted for intonation, the actual length of each string from the nut to the bridge saddle is slightly, but measurably longer than the scale length of the instrument. This additional length is called compensation, which flattens all notes a bit to compensate for the sharping of all fretted notes caused by stretching the string during fretting.
In major-thirds (M3) tuning, the chromatic scale is arranged on three consecutive strings in four consecutive frets.[83][84] This four-fret arrangement facilitates the left-hand technique for classical (Spanish) guitar:[84] For each hand position of four frets, the hand is stationary and the fingers move, each finger being responsible for exactly one fret.[85] Consequently, three hand-positions (covering frets 1–4, 5–8, and 9–12) partition the fingerboard of classical guitar,[86] which has exactly 12 frets.[note 1]
I've given this guitar chord book away as a gift and purchased one for myself. I love the spiral bound binding and I'm sure all but the best guitar players will not run out of chords to learn in this little book. I highly recommend this book to learn guitar chords. It's not a book that teaches you how to play a guitar. It is mostly chords but this is a crucial part of learning to play, right?
I have heard how giving you are in so many respects of music schooling and I must say that I am impressed. You remind me of the pure idealism that we had in starting Apple. If I were young, with time, I'd likely offer to join and help you in your endeavours. Keep making people happy, not just in their own learning, but in the example you set for them. 
The fingerboard, also called the fretboard, is a piece of wood embedded with metal frets that comprises the top of the neck. It is flat on classical guitars and slightly curved crosswise on acoustic and electric guitars. The curvature of the fretboard is measured by the fretboard radius, which is the radius of a hypothetical circle of which the fretboard's surface constitutes a segment. The smaller the fretboard radius, the more noticeably curved the fretboard is. Most modern guitars feature a 12" neck radius, while older guitars from the 1960s and 1970s usually feature a 6-8" neck radius. Pinching a string against a fret on fretboard effectively shortens the vibrating length of the string, producing a higher pitch.

At MI, you learn from a proven curriculum taught by the best guitar instructors in the world, augmented by visiting artists’ seminars, concerts, and lessons from some of the greatest players in contemporary music. At our guitar music college, you get to network with other players, find your creative voice, and get the training you need to become the player you have always dreamed of being.