+;;;; chord-entry.scm -- Generate chord names for the parser.
+;;;;
+;;;; source file of the GNU LilyPond music typesetter
+;;;;
+;;;; (c) 2004--2008 Han-Wen Nienhuys <hanwen@xs4all.nl>
+(define-public (construct-chord-elements root duration modifications)
+ " Build a chord on root using modifiers in MODIFICATIONS. NoteEvents
+have duration DURATION.
-(define (make-chord pitches bass duration)
- "Make EventChord with notes corresponding to PITCHES, BASS and DURATION. "
+Notes: natural 11 is left from chord if not explicitly specified.
+
+Entry point for the parser.
+"
+ (let* ((flat-mods (flatten-list modifications))
+ (base-chord (stack-thirds (ly:make-pitch 0 4 0) the-canonical-chord))
+ (complete-chord '())
+ (bass #f)
+ (inversion #f)
+ (lead-mod #f)
+ (explicit-11 #f)
+ (start-additions #t))
+
+ (define (interpret-inversion chord mods)
+ "Read /FOO part. Side effect: INVERSION is set."
+ (if (and (> (length mods) 1) (eq? (car mods) 'chord-slash))
+ (begin
+ (set! inversion (cadr mods))
+ (set! mods (cddr mods))))
+ (interpret-bass chord mods))
+
+ (define (interpret-bass chord mods)
+ "Read /+FOO part. Side effect: BASS is set."
+ (if (and (> (length mods) 1) (eq? (car mods) 'chord-bass))
+ (begin
+ (set! bass (cadr mods))
+ (set! mods (cddr mods))))
+ (if (pair? mods)
+ (scm-error 'chord-format "construct-chord" "Spurious garbage following chord: ~A" mods #f))
+ chord)
+
+ (define (interpret-removals chord mods)
+ (define (inner-interpret chord mods)
+ (if (and (pair? mods) (ly:pitch? (car mods)))
+ (inner-interpret (remove-step (+ 1 (ly:pitch-steps (car mods))) chord)
+ (cdr mods))
+ (interpret-inversion chord mods)))
+ (if (and (pair? mods) (eq? (car mods) 'chord-caret))
+ (inner-interpret chord (cdr mods))
+ (interpret-inversion chord mods)))
+
+ (define (interpret-additions chord mods)
+ "Interpret additions. TODO: should restrict modifier use?"
+ (cond ((null? mods) chord)
+ ((ly:pitch? (car mods))
+ (if (= (pitch-step (car mods)) 11)
+ (set! explicit-11 #t))
+ (interpret-additions (cons (car mods) (remove-step (pitch-step (car mods)) chord))
+ (cdr mods)))
+ ((procedure? (car mods))
+ (interpret-additions ((car mods) chord)
+ (cdr mods)))
+ (else (interpret-removals chord mods))))
+
+ (define (pitch-octavated-strictly-below p root)
+ "return P, but octavated, so it is below ROOT"
+ (ly:make-pitch (+ (ly:pitch-octave root)
+ (if (> (ly:pitch-notename root)
+ (ly:pitch-notename p))
+ 0 -1))
+ (ly:pitch-notename p)
+ (ly:pitch-alteration p)))
+
+ (define (process-inversion complete-chord)
+ "Take out inversion from COMPLETE-CHORD, and put it at the bottom.
+Return (INVERSION . REST-OF-CHORD).
+
+Side effect: put original pitch in INVERSION.
+If INVERSION is not in COMPLETE-CHORD, it will be set as a BASS, overriding
+the bass specified.
+
+"
+ (let* ((root (car complete-chord))
+ (inv? (lambda (y)
+ (and (= (ly:pitch-notename y)
+ (ly:pitch-notename inversion))
+ (= (ly:pitch-alteration y)
+ (ly:pitch-alteration inversion)))))
+ (rest-of-chord (remove inv? complete-chord))
+ (inversion-candidates (filter inv? complete-chord))
+ (down-inversion (pitch-octavated-strictly-below inversion root)))
+ (if (pair? inversion-candidates)
+ (set! inversion (car inversion-candidates))
+ (begin
+ (set! bass inversion)
+ (set! inversion #f)))
+ (if inversion
+ (cons down-inversion rest-of-chord)
+ rest-of-chord)))
+ ;; root is always one octave too low.
+ ;; something weird happens when this is removed,
+ ;; every other chord is octavated. --hwn... hmmm.
+ (set! root (ly:pitch-transpose root (ly:make-pitch 1 0 0)))
+ ;; skip the leading : , we need some of the stuff following it.
+ (if (pair? flat-mods)
+ (if (eq? (car flat-mods) 'chord-colon)
+ (set! flat-mods (cdr flat-mods))
+ (set! start-additions #f)))
+ ;; remember modifier
+ (if (and (pair? flat-mods) (procedure? (car flat-mods)))
+ (begin
+ (set! lead-mod (car flat-mods))
+ (set! flat-mods (cdr flat-mods))))
+ ;; extract first number if present, and build pitch list.
+ (if (and (pair? flat-mods)
+ (ly:pitch? (car flat-mods))
+ (not (eq? lead-mod sus-modifier)))
+ (begin
+ (if (= (pitch-step (car flat-mods)) 11)
+ (set! explicit-11 #t))
+ (set! base-chord
+ (stack-thirds (car flat-mods) the-canonical-chord))
+ (set! flat-mods (cdr flat-mods))))
+ ;; apply modifier
+ (if (procedure? lead-mod)
+ (set! base-chord (lead-mod base-chord)))
+ (set! complete-chord
+ (if start-additions
+ (interpret-additions base-chord flat-mods)
+ (interpret-removals base-chord flat-mods)))
+ (set! complete-chord (sort complete-chord ly:pitch<?))
+ ;; If natural 11 + natural 3 is present, but not given explicitly,
+ ;; we remove the 11.
+ (if (and (not explicit-11)
+ (get-step 11 complete-chord)
+ (get-step 3 complete-chord)
+ (= 0 (ly:pitch-alteration (get-step 11 complete-chord)))
+ (= 0 (ly:pitch-alteration (get-step 3 complete-chord))))
+ (set! complete-chord (remove-step 11 complete-chord)))
+ ;; must do before processing inversion/bass, since they are
+ ;; not relative to the root.
+ (set! complete-chord (map (lambda (x) (ly:pitch-transpose x root))
+ complete-chord))
+ (if inversion
+ (set! complete-chord (process-inversion complete-chord)))
+ (if bass
+ (set! bass (pitch-octavated-strictly-below bass root)))
+ (if #f
+ (begin
+ (write-me "\n*******\n" flat-mods)
+ (write-me "root: " root)
+ (write-me "base chord: " base-chord)
+ (write-me "complete chord: " complete-chord)
+ (write-me "inversion: " inversion)
+ (write-me "bass: " bass)))
+ (if inversion
+ (make-chord-elements (cdr complete-chord) bass duration (car complete-chord)
+ inversion)
+ (make-chord-elements complete-chord bass duration #f #f))))
+
+
+(define (make-chord-elements pitches bass duration inversion original-inv-pitch)
+ "Make EventChord with notes corresponding to PITCHES, BASS and
+DURATION, and INVERSION."
(define (make-note-ev pitch)
- (let*
- (
- (ev (make-music-by-name 'NoteEvent))
- )
-
- (ly:set-mus-property! ev 'duration duration)
- (ly:set-mus-property! ev 'pitch pitch)
- ev
- ))
-
- (let*
- (
- (nots (map make-note-ev pitches))
- (bass-note (if bass (make-note-ev bass) #f))
- )
-
+ (make-music 'NoteEvent
+ 'duration duration
+ 'pitch pitch))
+ (let ((nots (map make-note-ev pitches))
+ (bass-note (if bass (make-note-ev bass) #f))
+ (inv-note (if inversion (make-note-ev inversion) #f)))
(if bass-note
(begin
- (ly:set-mus-property! bass-note 'bass #t)
+ (set! (ly:music-property bass-note 'bass) #t)
(set! nots (cons bass-note nots))))
+ (if inv-note
+ (begin
+ (set! (ly:music-property inv-note 'inversion) #t)
+ (set! (ly:music-property inv-note 'octavation)
+ (- (ly:pitch-octave inversion)
+ (ly:pitch-octave original-inv-pitch)))
+ (set! nots (cons inv-note nots))))
+ nots))
- (make-event-chord nots)
- ))
+;;;;;;;;;;;;;;;;
+; chord modifiers change the pitch list.
+(define (aug-modifier pitches)
+ (set! pitches (replace-step (ly:make-pitch 0 4 SHARP) pitches))
+ (replace-step (ly:make-pitch 0 2 0) pitches))
-(define (aug-modifier root pitches)
- (set! pitches (replace-step (ly:pitch-transpose (ly:make-pitch 0 4 1) root) pitches))
- (replace-step (ly:pitch-transpose (ly:make-pitch 0 2 0) root) pitches)
- )
+(define (minor-modifier pitches)
+ (replace-step (ly:make-pitch 0 2 FLAT) pitches))
+(define (maj7-modifier pitches)
+ (set! pitches (remove-step 7 pitches))
+ (cons (ly:make-pitch 0 6 0) pitches))
-(define (minor-modifier root pitches)
- (replace-step (ly:pitch-transpose (ly:make-pitch 0 2 -1) root) pitches)
- )
+(define (dim-modifier pitches)
+ (set! pitches (replace-step (ly:make-pitch 0 2 FLAT) pitches))
+ (set! pitches (replace-step (ly:make-pitch 0 4 FLAT) pitches))
+ (set! pitches (replace-step (ly:make-pitch 0 6 DOUBLE-FLAT) pitches))
+ pitches)
-(define (maj7-modifier root pitches)
- (set! pitches (remove-step 7 pitches))
- (cons (ly:pitch-transpose (ly:make-pitch 0 6 0) root) pitches)
- )
-
-(define (dim-modifier root pitches)
- (set! pitches (replace-step (ly:pitch-transpose (ly:make-pitch 0 2 -1) root) pitches))
- (set! pitches (replace-step (ly:pitch-transpose (ly:make-pitch 0 4 -1) root) pitches))
- (set! pitches (replace-step (ly:pitch-transpose (ly:make-pitch 0 6 -2) root) pitches))
- pitches
- )
-
-
-(define (sus2-modifier root pitches)
- (set! pitches (remove-step (pitch-step (ly:pitch-transpose (ly:make-pitch 0 2 0) root)) pitches))
- (set! pitches (remove-step (pitch-step (ly:pitch-transpose (ly:make-pitch 0 3 0) root)) pitches))
- (cons (ly:pitch-transpose (ly:make-pitch 0 1 0) root) pitches)
- )
-
-(define (sus4-modifier root pitches)
- (set! pitches (remove-step (pitch-step (ly:pitch-transpose (ly:make-pitch 0 2 0) root)) pitches))
- (set! pitches (remove-step (pitch-step (ly:pitch-transpose (ly:make-pitch 0 3 0) root)) pitches))
- (cons (ly:pitch-transpose (ly:make-pitch 0 3 0) root) pitches)
- )
-
-(define-public default-chord-modifier-list
+(define (sus-modifier pitches)
+ (remove-step (pitch-step (ly:make-pitch 0 2 0)) pitches))
+
+(define-safe-public default-chord-modifier-list
`((m . ,minor-modifier)
(min . ,minor-modifier)
(aug . , aug-modifier)
(dim . , dim-modifier)
(maj . , maj7-modifier)
- (sus . , sus4-modifier)
- ))
-
-(define (gobble-pitches lst)
- (if (null? lst)
- '()
- (if (ly:pitch? (car lst))
- (gobble-pitches (cdr lst))
- lst
- )))
-
-
-;; ? should remove 3 if sus2 or sus4 found?
-(define (add-pitches root pitches to-add)
- (if
- (or (null? to-add) (not (ly:pitch? (car to-add))))
- pitches
- (let*
- (
- (p (ly:pitch-transpose (car to-add) root))
- (step (pitch-step p))
- )
- (if (get-step step pitches)
- (set! pitches (remove-step step pitches)))
- (add-pitches root (cons p pitches) (cdr to-add)))))
-
-(define (rm-pitches root pitches to-add)
- (if
- (or (null? to-add) (not (ly:pitch? (car to-add))))
- pitches
- (let*
- (
- (p (ly:pitch-transpose (car to-add) root))
- (step (pitch-step p))
- )
- (rm-pitches root (remove-step step pitches) (cdr to-add)))))
-
-
-(define-public (construct-chord root duration modifications)
- (let*
- (
- (flat-mods (flatten-list modifications))
- (base-chord (list root
- (ly:pitch-transpose (ly:make-pitch 0 2 0) root)
- (ly:pitch-transpose (ly:make-pitch 0 4 0) root)))
- (complete-chord '())
- (bass #f)
- (inversion #f)
- )
-
- (define (process-inversion note-evs inversion)
-
- ;; TODO
- ;; Transpose the inversion down, and remember its original octave.
- note-evs
- )
-
- (define (interpret-chord root chord mods)
- "Walk MODS, and apply each mod to CHORD in turn.
-
-Side-effect: set BASS and INVERSION in containing body
-"
- ;; the recursion makes this into a loop. Perhaps its better to
- ;; to do the different types of modifiers in order, so that
- ;; addition _always_ precedes removal.
- (if (null? mods)
- chord
- (let* (
- (tag (car mods))
- (tail (cdr mods))
- )
- (cond
- ((procedure? tag)
- (interpret-chord root
- (tag root chord)
- tail))
- ((equal? tag 'chord-colon)
- (interpret-chord root
- (add-pitches root chord tail)
- (gobble-pitches tail)))
- ((equal? tag 'chord-caret)
- (interpret-chord root
- (rm-pitches root chord tail)
- (gobble-pitches tail)))
-
- ((equal? tag 'chord-slash)
- (set! inversion (car tail))
- (interpret-chord root
- chord
- (gobble-pitches tail)))
- ((equal? tag 'chord-bass)
- (set! bass (car tail))
- (interpret-chord root
- chord
- (gobble-pitches tail)))
-
- ;; ugh. Simply add isolated pitches. This will give
- ;; unexpected results....
- ((ly:pitch? tag)
- (interpret-chord root
- (add-pitches root chord tail)
- (gobble-pitches tail)))
- (else (scm-error 'chord-entry 'interpret-chord "Unknown chord instructions ~S." (list mods) #f))
- )
- )
- ))
-
- (write-me "*******\n" flat-mods)
- (write-me "pitches: " complete-chord)
- (write-me "bass: " bass)
-
- (set! complete-chord (interpret-chord root base-chord flat-mods))
- (set! complete-chord (sort complete-chord ly:pitch<?))
-
- ;; TODO: lower bass to be below chord.
- (process-inversion (make-chord complete-chord bass duration) inversion)
-
- ))
+ (sus . , sus-modifier)))
+
+;; canonical 13 chord.
+(define the-canonical-chord
+ (map (lambda (n)
+ (define (nca x)
+ (if (= x 7) FLAT 0))
+
+ (if (>= n 8)
+ (ly:make-pitch 1 (- n 8) (nca n))
+ (ly:make-pitch 0 (- n 1) (nca n))))
+ '(1 3 5 7 9 11 13)))
+
+(define (stack-thirds upper-step base)
+ "Stack thirds listed in BASE until we reach UPPER-STEP. Add
+UPPER-STEP separately."
+ (cond ((null? base) '())
+ ((> (ly:pitch-steps upper-step) (ly:pitch-steps (car base)))
+ (cons (car base) (stack-thirds upper-step (cdr base))))
+ ((<= (ly:pitch-steps upper-step) (ly:pitch-steps (car base)))
+ (list upper-step))
+ (else '())))
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