Piano ↔ guitar

A piano lays every note out in one line, left to right. A guitar folds that line onto six strings: the same note turns up in several places, and moving one fret is moving one key.

Below is the G major scale both ways, each note numbered and coloured the same. The piano shows why it sounds the way it does (whole steps and two half steps, at 3–4 and 7–1); the guitar shows where your fingers go.