2 ;;; Generate chord names for the parser.
6 (define-public (construct-chord root duration modifications)
8 " Build a chord on root using modifiers in MODIFICATIONS. NoteEvent
9 have duration DURATION..
11 Notes: natural 11 is left from chord if not explicitly specified.
13 Entry point for the parser.
18 (flat-mods (flatten-list modifications))
19 (base-chord (stack-thirds (ly:make-pitch 0 4 0) the-canonical-chord))
28 (define (interpret-inversion chord mods)
29 "Read /FOO part. Side effect: INVERSION is set."
31 (if (and (> (length mods) 1) (eq? (car mods) 'chord-slash))
33 (set! inversion (cadr mods))
34 (set! mods (cddr mods))))
36 (interpret-bass chord mods))
38 (define (interpret-bass chord mods)
39 "Read /+FOO part. Side effect: BASS is set."
41 (if (and (> (length mods) 1) (eq? (car mods) 'chord-bass))
43 (set! bass (cadr mods))
44 (set! mods (cddr mods))))
47 (scm-error 'chord-format "construct-chord" "Spurious garbage following chord: ~A" mods #f)
53 (define (interpret-removals chord mods)
54 (define (inner-interpret chord mods)
55 (if (and (pair? mods) (ly:pitch? (car mods)))
57 (remove-step (+ 1 (ly:pitch-steps (car mods))) chord)
59 (interpret-inversion chord mods))
62 (if (and (pair? mods) (eq? (car mods) 'chord-caret))
63 (inner-interpret chord (cdr mods))
64 (interpret-inversion chord mods))
68 (define (interpret-additions chord mods)
69 "Interpret additions. TODO: should restrict modifier use?"
72 ((ly:pitch? (car mods))
73 (if (= (ly:pitch-steps (car mods)) 11)
74 (set! explicit-11 #t))
76 (cons (car mods) (remove-step (pitch-step (car mods)) chord))
78 ((procedure? (car mods))
82 (else (interpret-removals chord mods))
85 (define (pitch-octavated-strictly-below p root)
86 "return P, but octavated, so it is below ROOT"
89 (ly:pitch-octave root)
90 (if (> (ly:pitch-notename root)
91 (ly:pitch-notename p))
94 (ly:pitch-alteration p)))
96 (define (process-inversion complete-chord)
97 "Take out inversion from COMPLETE-CHORD, and put it at the bottom.
98 Return (INVERSION . REST-OF-CHORD).
100 Side effect: put original pitch in INVERSION.
101 If INVERSION is not in COMPLETE-CHORD, it will be set as a BASS, overriding
107 (root (car complete-chord))
109 (and (= (ly:pitch-notename y)
110 (ly:pitch-notename inversion))
111 (= (ly:pitch-alteration y)
112 (ly:pitch-alteration inversion))
115 (rest-of-chord (filter-out-list inv? complete-chord))
116 (inversion-candidates (filter-list inv? complete-chord))
117 (down-inversion (pitch-octavated-strictly-below inversion root))
120 (if (pair? inversion-candidates)
121 (set! inversion (car inversion-candidates))
123 (set! bass inversion)
127 (cons down-inversion rest-of-chord)
132 ;; root is always one octave too low.
134 ; something weird happens when this is removed,
135 ; every other chord is octavated. --hwn... hmmm.
136 (set! root (ly:pitch-transpose root (ly:make-pitch 1 0 0)))
138 ;; skip the leading : , we need some of the stuff following it.
139 (if (pair? flat-mods)
140 (if (eq? (car flat-mods) 'chord-colon)
141 (set! flat-mods (cdr flat-mods))
142 (set! start-additions #f)
146 (if (and (pair? flat-mods) (procedure? (car flat-mods)))
148 (set! lead-mod (car flat-mods))
149 (set! flat-mods (cdr flat-mods))
152 ;; extract first number if present, and build pitch list.
153 (if (and (pair? flat-mods)
154 (ly:pitch? (car flat-mods))
155 (not (eq? lead-mod sus-modifier))
159 (if (= (pitch-step (car flat-mods)) 11)
160 (set! explicit-11 #t))
162 (stack-thirds (car flat-mods) the-canonical-chord))
163 (set! flat-mods (cdr flat-mods))
167 (if (procedure? lead-mod)
168 (set! base-chord (lead-mod base-chord)))
173 (interpret-additions base-chord flat-mods)
174 (interpret-removals base-chord flat-mods)
178 (set! complete-chord (map (lambda (x) (ly:pitch-transpose x root))
179 (sort complete-chord ly:pitch<?)))
181 ;; If natural 11 + natural 3 is present, but not given explicitly,
183 (if (and (not explicit-11)
184 (get-step 11 complete-chord)
185 (get-step 3 complete-chord)
186 (= 0 (ly:pitch-alteration (get-step 11 complete-chord)))
187 (= 0 (ly:pitch-alteration (get-step 3 complete-chord)))
190 (set! complete-chord (remove-step 11 complete-chord))
194 (set! complete-chord (process-inversion complete-chord)))
196 (set! bass (pitch-octavated-strictly-below bass root)))
200 (write-me "\n*******\n" flat-mods)
201 (write-me "root: " root)
202 (write-me "base chord: " base-chord)
203 (write-me "complete chord: " complete-chord)
204 (write-me "inversion: " inversion)
205 (write-me "bass: " bass)))
210 (make-chord (cdr complete-chord) bass duration (car complete-chord)
212 (make-chord complete-chord bass duration #f #f))
216 (define (make-chord pitches bass duration inversion original-inv-pitch)
217 "Make EventChord with notes corresponding to PITCHES, BASS and
218 DURATION, and INVERSION."
219 (define (make-note-ev pitch)
222 (ev (make-music-by-name 'NoteEvent))
225 (ly:set-mus-property! ev 'duration duration)
226 (ly:set-mus-property! ev 'pitch pitch)
232 (nots (map make-note-ev pitches))
233 (bass-note (if bass (make-note-ev bass) #f))
234 (inv-note (if inversion (make-note-ev inversion) #f))
240 (ly:set-mus-property! bass-note 'bass #t)
241 (set! nots (cons bass-note nots))))
246 (ly:set-mus-property! inv-note 'inversion #t)
247 (ly:set-mus-property! inv-note 'original-pitch original-inv-pitch)
248 (set! nots (cons inv-note nots))))
250 (make-event-chord nots)
255 ; chord modifiers change the pitch list.
257 (define (aug-modifier pitches)
258 (set! pitches (replace-step (ly:make-pitch 0 4 1) pitches))
259 (replace-step (ly:make-pitch 0 2 0) pitches)
262 (define (minor-modifier pitches)
263 (replace-step (ly:make-pitch 0 2 -1) pitches)
266 (define (maj7-modifier pitches)
267 (set! pitches (remove-step 7 pitches))
268 (cons (ly:make-pitch 0 6 0) pitches)
271 (define (dim-modifier pitches)
272 (set! pitches (replace-step (ly:make-pitch 0 2 -1) pitches))
273 (set! pitches (replace-step (ly:make-pitch 0 4 -1) pitches))
274 (set! pitches (replace-step (ly:make-pitch 0 6 -2) pitches))
278 (define (sus-modifier pitches)
279 (remove-step (pitch-step (ly:make-pitch 0 2 0)) pitches)
282 (define-public default-chord-modifier-list
283 `((m . ,minor-modifier)
284 (min . ,minor-modifier)
285 (aug . , aug-modifier)
286 (dim . , dim-modifier)
287 (maj . , maj7-modifier)
288 (sus . , sus-modifier)
292 ;; canonical 13 chord.
293 (define the-canonical-chord
299 (ly:make-pitch 1 (- n 8) (nca n))
300 (ly:make-pitch 0 (- n 1) (nca n))))
303 (define (stack-thirds upper-step base)
304 "Stack thirds listed in BASE until we reach UPPER-STEP. Add
305 UPPER-STEP separately."
308 ((> (ly:pitch-steps upper-step) (ly:pitch-steps (car base)))
309 (cons (car base) (stack-thirds upper-step (cdr base))))
310 ((<= (ly:pitch-steps upper-step) (ly:pitch-steps (car base)))