Before tuning a guitar, first learn the name of each string. A guitar has six: the first string is on the bottom, and it's the thinnest. The sixth string is on the top, and it's the thickest. Starting at the bottom, the notes are E, B, G, D, A, and E.
If you have an electric tuner, hold it near the guitar and pluck the high E string (the one on the bottom) first. The tuner will determine whether the note produced by the string is flat (too low) or sharp (too high). Pick each of the remaining strings. Depending on what the tuner tells you, loosen the string to make the note lower or tighten it to make the note higher. Which author's purpose is suggested by the text?