While four years old is a little young for formal guitar lessons, it's not too early to begin teaching your child musical concepts that will be important once they are old enough for guitar instruction at School of Rock. Your 4-year-old can participate in the Little Wing music program to learn fundamental concepts through fun, dynamic musical activities. 

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]
Unlike many string instruments which use a bow to create a sound, guitars are played by plucking or strumming the strings on the instrument, which vibrate to create a sound. Chords are played when the guitarist holds their fingers down on more than one individual string to change its length, which in turn changes the frequency of the vibration created - in other words, it creates a different note. Performers often use guitar tabs, rather than sheet music, when learning music: this acts as a kind of 'map' to teach guitarists where to put their fingers on the strings.