• The horizontal lines are the strings, with the treble on top and the bass at the bottom.
  • The vertical lines are the frets. (The peghead is somewhere on the left.)
  • The numbers are the numbered major scale. Depending on what major scale the chord is based on, the chart shows different parts of the fretboard.
1) Determine what notes you need for the chord.
For a F#m7 chord, you need 1, -3, 5, -7, not specifically in that order.
The note 1 = F# = the root.
2) Determine where on the fretboard you want to place the chord. Find the root of the chord somewhere in that area. On witch string is it?
3) Find number 1 on the corresponding string on the chart.  If there are two number 1, choose the 1 that gives the best overview. The chart shows where the rest of the chord notes are located in relation to the root. You can see every possible way to make the chord.