+
+@node Predefined fret diagrams
+@unnumberedsubsubsec Predefined fret diagrams
+
+
+@cindex fret diagrams
+@cindex chord diagrams
+
+@funindex FretBoards
+@funindex stringTunings
+
+Fret diagrams can be displayed using the @code{FretBoards} context. By
+default, the @code{FretBoards} context will display fret diagrams that
+are stored in a lookup table:
+
+@lilypond[verbatim, ragged-right, quote]
+\include "predefined-guitar-fretboards.ly"
+\context FretBoards {
+ \chordmode {
+ c1 d
+ }
+}
+@end lilypond
+
+The default predefined fret diagrams are contained in the file
+@code{predefined-guitar-fretboards.ly}. Fret diagrams are
+stored based on the pitches of a chord and the value of
+@code{stringTunings} that is currently in use.
+@code{predefined-guitar-fretboards.ly} contains predefined
+fret diagrams only for @code{guitar-tuning}. Predefined fret
+diagrams can be added for other instruments or other tunings
+by following the examples found in
+@code{predefined-guitar-fretboards.ly}.
+
+Chord pitches can be entered
+either as simultaneous music or using chord mode (see
+@ref{Chord mode overview}).
+
+@lilypond[verbatim, ragged-right,quote]
+\include "predefined-guitar-fretboards.ly"
+\context FretBoards {
+ \chordmode {c1}
+ <c' e' g'>1
+}
+@end lilypond
+
+@cindex chord names with fret diagrams
+@cindex fret diagrams with chord names
+
+@funindex ChordNames
+@funindex chordmode
+@funindex \chordmode
+
+It is common that both chord names and fret diagrams are displayed together.
+This is achieved by putting a @code{ChordNames} context in parallel with
+a @code{FretBoards} context and giving both contexts the same music.
+
+@lilypond[verbatim, ragged-right, quote]
+\include "predefined-guitar-fretboards.ly"
+mychords = \chordmode{
+ c1 f g
+}
+
+<<
+ \context ChordNames {
+ \mychords
+ }
+ \context FretBoards {
+ \mychords
+ }
+>>
+@end lilypond
+
+@cindex transposing fret diagrams
+@cindex fret diagrams, transposing
+@cindex diagrams, fret, transposing
+
+Predefined fret diagrams are transposable, as long as a diagram for the
+transposed chord is stored in the fret diagram table.
+
+@lilypond[verbatim, ragged-right, quote]
+\include "predefined-guitar-fretboards.ly"
+mychords = \chordmode{
+ c1 f g
+}
+
+mychordlist = {
+ \mychords
+ \transpose c e { \mychords}
+}
+<<
+ \context ChordNames {
+ \mychordlist
+ }
+ \context FretBoards {
+ \mychordlist
+ }
+>>
+@end lilypond
+
+
+The predefined fret diagram table contains seven chords (major, minor,
+augmented, diminished, dominant seventh, major seventh, minor seventh)
+for each of 17 keys. A complete list of the predefined fret diagrams is
+shown in @ref{Predefined fretboard diagrams}. If there is no entry in
+the table for a chord, the FretBoards engraver will calculate a
+fret-diagram using the automatic fret diagram functionality described in
+@ref{Automatic fret diagrams}.
+
+@lilypond[verbatim, ragged-right, quote]
+\include "predefined-guitar-fretboards.ly"
+mychords = \chordmode{
+ c1 c:9
+}
+
+<<
+ \context ChordNames {
+ \mychords
+ }
+ \context FretBoards {
+ \mychords
+ }
+>>
+@end lilypond
+
+@cindex fret diagrams, adding custom
+@cindex custom fret diagrams, adding
+@cindex adding custom fret diagrams
+
+Fret diagrams can be added to the fret diagram table. To add a diagram,
+you must specify the chord for the diagram, the tuning to be used, and the
+fret-diagram-terse definition string for the diagram.
+
+@lilypond[verbatim, ragged-right, quote]
+\include "predefined-guitar-fretboards.ly"
+
+\storePredefinedDiagram \chordmode {c:9}
+ #guitar-tuning
+ #"x;3-2;2-1;3-3;3-4;x;"
+
+mychords = \chordmode{
+ c1 c:9
+}
+
+<<
+ \context ChordNames {
+ \mychords
+ }
+ \context FretBoards {
+ \mychords
+ }
+>>
+@end lilypond
+
+Different fret diagrams for the same chord name can be stored using different
+octaves of pitches.
+
+@lilypond[verbatim, ragged-right, quote]
+\include "predefined-guitar-fretboards.ly"
+
+\storePredefinedDiagram \chordmode {c'}
+ #guitar-tuning
+ #(offset-fret 2 (chord-shape 'bes))
+
+mychords = \chordmode{
+ c1 c'
+}
+
+<<
+ \context ChordNames {
+ \mychords
+ }
+ \context FretBoards {
+ \mychords
+ }
+>>
+@end lilypond
+
+@cindex fretted instruments, chord shapes
+@cindex chord shapes for fretted instruments
+
+@funindex \addChordShape
+@funindex add ChordShape
+@funindex storePredefinedDiagram
+@funindex \storePredefinedDiagram
+
+In addition to fret diagrams, LilyPond stores an internal list of chord
+shapes. The chord shapes are fret diagrams that can be shifted along
+the neck to different posistions to provide different chords. Chord
+shapes can be added to the internal list and then used to define
+predefined fret diagrams.
+
+@lilypond[verbatim, ragged-right, quote]
+\include "predefined-guitar-fretboards.ly"
+
+% add a new chord shape
+
+\addChordShape #'powerf #"1-1;3-3;3-4;x;x;x;"
+
+% add some new chords based on the power chord shape
+
+\storePredefinedDiagram \chordmode {f'}
+ #guitar-tuning
+ #(chord-shape 'powerf)
+\storePredefinedDiagram \chordmode {g'}
+ #guitar-tuning
+ #(offset-fret 2 (chord-shape 'powerf))
+
+mychords = \chordmode{
+ f1 f' g g'
+}
+
+<<
+ \context ChordNames {
+ \mychords
+ }
+ \context FretBoards {
+ \mychords
+ }
+>>
+@end lilypond
+
+The graphical layout of a fret diagram can be customized according to
+user preference through the properties of the @code{fret-diagram-interface}.
+Details are found at @rinternals{fret-diagram-interface}. For a
+predefined fret diagram, the interface properties belong to
+@code{FretBoards.FretBoard}.
+
+@snippets
+
+@lilypondfile[verbatim,lilyquote,texidoc,doctitle]
+{customizing-fretboard-fret-diagrams.ly}
+
+@lilypondfile[verbatim,lilyquote,texidoc,doctitle]
+{defining-predefined-fretboards-for-other-instruments.ly}
+
+
+@seealso
+Notation Reference:
+@ref{Custom tablatures},
+@ref{Automatic fret diagrams},
+@ref{Chord mode overview},
+@ref{Predefined fretboard diagrams}.
+
+Installed Files:
+@file{ly/predefined-guitar-fretboards.ly},
+@file{ly/predefined-guitar-ninth-fretboards.ly}.
+
+Snippets:
+@rlsr{Fretted strings}.
+
+Internals Reference:
+@rinternals {fret-diagram-interface}.
+
+
+@node Automatic fret diagrams
+@unnumberedsubsubsec Automatic fret diagrams
+
+@cindex fret diagrams, automatic
+@cindex chord diagrams, automatic
+@cindex automatic fret diagrams
+@cindex automatic chord diagrams
+
+Fret diagrams can be automatically created from entered notes using the
+@code{FretBoards} context. If no predefined diagram is available for
+the entered notes in the active @code{stringTunings}, this context
+calculates strings and frets that can be used to play the notes.
+
+@lilypond[quote,ragged-right,verbatim]
+<<
+ \context ChordNames {
+ \chordmode {
+ f1 g
+ }
+ }
+ \context FretBoards {
+ < f, c f a c' f'>1
+ < g,\6 b, d g b g'>
+ }
+ \context Staff {
+ \clef "treble_8"
+ < f, c f a c' f'>1
+ < g, b, d g b' g'>
+ }
+>>
+@end lilypond
+
+@funindex predefinedFretboardsOff
+@funindex \predefinedFretboardsOff
+@funindex predefinedFretboardsOn
+@funindex \predefinedFretboardsOn
+
+As no predefined diagrams are loaded by default, automatic calculation
+of fret diagrams is the default behavior. Once default diagrams are
+loaded, automatic calculation can be enabled and disabled with predefined
+commands:
+
+@lilypond[quote,ragged-right,verbatim]
+
+\storePredefinedDiagram <c e g c' e'>
+ #guitar-tuning
+ #"x;3-1-(;5-2;5-3;5-4;3-1-1);"
+<<
+ \context ChordNames {
+ \chordmode {
+ c1 c c
+ }
+ }
+ \context FretBoards {
+ <c e g c' e'>1
+ \predefinedFretboardsOff
+ <c e g c' e'>
+ \predefinedFretboardsOn
+ <c e g c' e'>
+ }
+ \context Staff {
+ \clef "treble_8"
+ <c e g c' e'>1
+ <c e g c' e'>
+ <c e g c' e'>
+ }
+>>
+@end lilypond
+
+
+
+Sometimes the fretboard calculator will be unable to find
+an accceptable diagram. This can often be remedied by
+manually assigning a note to a string. In many cases, only one
+note need be manually placed on a string; the rest of
+the notes will then be placed appropriately by the @code{FretBoards}
+context.
+
+@cindex fret diagrams, adding fingerings
+@cindex fingerings, adding to fret diagrams
+
+Fingerings can be added to FretBoard fret diagrams.
+
+@lilypond[quote, verbatim]
+<<
+ \context ChordNames {
+ \chordmode {
+ c1 d:m
+ }
+ }
+ \context FretBoards {
+ < c-3 e-2 g c'-1 e' > 1
+ < d a-2 d'-3 f'-1>
+ }
+ \context Staff {
+ \clef "treble_8"
+ < c e g c' e' > 1
+ < d a d' f'>
+ }
+>>
+@end lilypond
+
+The minimum fret to be used in calculating strings and frets for
+the FretBoard context can be set with the @code{minimumFret}
+property.
+
+@lilypond[quote, verbatim]
+<<
+ \context ChordNames {
+ \chordmode {
+ d1:m d:m
+ }
+ }
+ \context FretBoards {
+ < d a d' f'>
+ \set FretBoards.minimumFret = #5
+ < d a d' f'>
+ }
+ \context Staff {
+ \clef "treble_8"
+ < d a d' f'>
+ < d a d' f'>
+ }
+>>
+@end lilypond
+
+The strings and frets for the @code{FretBoards} context depend
+on the @code{stringTunings} property, which has the same meaning
+as in the TabStaff context. See @ref{Custom tablatures} for
+information on the @code{stringTunings} property.
+
+The graphical layout of a fret diagram can be customized according to
+user preference through the properties of the @code{fret-diagram-interface}.
+Details are found at @rinternals{fret-diagram-interface}. For a
+@code{FretBoards} fret diagram, the interface properties belong to
+@code{FretBoards.FretBoard}.
+
+
+@predefined
+@code{\predefinedFretboardsOff},
+@code{\predefinedFretboardsOn}.
+@endpredefined
+
+
+@seealso
+Notation Reference:
+@ref{Custom tablatures}.
+
+Snippets:
+@rlsr{Fretted strings}.
+
+Internals Reference:
+@rinternals {fret-diagram-interface}.
+
+