To change the working range of your fretboard click on the menu tab Range
→ Selected Frets. The range
begins at fret 0 which is the open position (nut) to maximally fret 36.
The default shown goes from fret 0 to fret 20. Make your selection in
the popups (From To).
Then you may want to change the displayed frets accordingly. Because the spacing
gets progressively smaller towards higher frets, you can (Settings
→ Fretspacing even) switch
to a view with evenly spaced frets.
The used fret range will be indicated by dark fret numbers (here Fret 1 to Fret
14) the remaining unused but displayed fret numbers will be of a lighter color
(here Fret 14 to Fret 20). Reminder: Settings
→ Show/Hide Numbers lets you toggle
between numbers on/off. Throwing in a capo overrides your selected fret selection.
Notes can only be played or shown in the Selected
Fret Range.
