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 (process-inversion complete-chord)
86 "Take out inversion from COMPLETE-CHORD, and put it at the bottom.
87 Return (INVERSION . REST-OF-CHORD).
89 Side effect: put original pitch in INVERSION.
93 (root (car complete-chord))
95 (= (ly:pitch-notename y)
96 (ly:pitch-notename inversion))))
97 (rest-of-chord (filter-out-list inv? complete-chord))
98 (inversion-candidates (filter-list inv? complete-chord))
99 (down-inversion (ly:make-pitch
101 (ly:pitch-octave root)
102 (if (>= (ly:pitch-notename root)
103 (ly:pitch-notename inversion))
105 (ly:pitch-notename inversion)
106 (ly:pitch-alteration inversion)))
109 (if (pair? inversion-candidates)
110 (set! inversion (car inversion-candidates)))
112 (cons down-inversion rest-of-chord)
115 ;; root is always one octave too low.
117 ; something weird happens when this is removed,
118 ; every other chord is octavated. --hwn... hmmm.
119 (set! root (ly:pitch-transpose root (ly:make-pitch 1 0 0)))
123 (write-me "\n*******\n" flat-mods)
124 (write-me "root: " root)
125 (write-me "base: " base-chord)
126 (write-me "bass: " bass)))
128 ;; skip the leading : , we need some of the stuff following it.
129 (if (pair? flat-mods)
130 (if (eq? (car flat-mods) 'chord-colon)
131 (set! flat-mods (cdr flat-mods))
132 (set! start-additions #f)
136 (if (and (pair? flat-mods) (procedure? (car flat-mods)))
138 (set! lead-mod (car flat-mods))
139 (set! flat-mods (cdr flat-mods))
142 ;; extract first number if present, and build pitch list.
143 (if (and (pair? flat-mods)
144 (ly:pitch? (car flat-mods))
145 (not (eq? lead-mod sus-modifier))
149 (if (= (pitch-step (car flat-mods)) 11)
150 (set! explicit-11 #t))
152 (map (lambda (y) (ly:pitch-transpose y root))
153 (stack-thirds (car flat-mods) the-canonical-chord)))
154 (set! flat-mods (cdr flat-mods))
158 (if (procedure? lead-mod)
159 (set! base-chord (lead-mod base-chord)))
164 (interpret-additions base-chord flat-mods)
165 (interpret-removals base-chord flat-mods)
169 (set! complete-chord (map (lambda (x) (ly:pitch-transpose x root))
170 (sort complete-chord ly:pitch<?)))
172 ;; If natural 11 + natural 3 is present, but not given explicitly,
174 (if (and (not explicit-11)
175 (get-step 11 complete-chord)
176 (get-step 3 complete-chord)
177 (= 0 (ly:pitch-alteration (get-step 11 complete-chord)))
178 (= 0 (ly:pitch-alteration (get-step 3 complete-chord)))
181 (set! complete-chord (remove-step 11 complete-chord))
186 (set! complete-chord (process-inversion complete-chord))
187 (make-chord (cdr complete-chord) bass duration (car complete-chord)
190 (make-chord complete-chord bass duration #f #f))
194 (define (make-chord pitches bass duration inversion original-inv-pitch)
195 "Make EventChord with notes corresponding to PITCHES, BASS and
196 DURATION, and INVERSION."
197 (define (make-note-ev pitch)
200 (ev (make-music-by-name 'NoteEvent))
203 (ly:set-mus-property! ev 'duration duration)
204 (ly:set-mus-property! ev 'pitch pitch)
210 (nots (map make-note-ev pitches))
211 (bass-note (if bass (make-note-ev bass) #f))
212 (inv-note (if inversion (make-note-ev inversion) #f))
218 (ly:set-mus-property! bass-note 'bass #t)
219 (set! nots (cons bass-note nots))))
224 (ly:set-mus-property! inv-note 'inversion #t)
225 (ly:set-mus-property! inv-note 'original-pitch original-inv-pitch)
226 (set! nots (cons inv-note nots))))
228 (make-event-chord nots)
233 ; chord modifiers change the pitch list.
235 (define (aug-modifier pitches)
236 (set! pitches (replace-step (ly:make-pitch 0 4 1) pitches))
237 (replace-step (ly:make-pitch 0 2 0) pitches)
240 (define (minor-modifier pitches)
241 (replace-step (ly:make-pitch 0 2 -1) pitches)
244 (define (maj7-modifier pitches)
245 (set! pitches (remove-step 7 pitches))
246 (cons (ly:make-pitch 0 6 0) pitches)
249 (define (dim-modifier pitches)
250 (set! pitches (replace-step (ly:make-pitch 0 2 -1) pitches))
251 (set! pitches (replace-step (ly:make-pitch 0 4 -1) pitches))
252 (set! pitches (replace-step (ly:make-pitch 0 6 -2) pitches))
256 (define (sus-modifier pitches)
257 (remove-step (pitch-step (ly:make-pitch 0 2 0)) pitches)
260 (define-public default-chord-modifier-list
261 `((m . ,minor-modifier)
262 (min . ,minor-modifier)
263 (aug . , aug-modifier)
264 (dim . , dim-modifier)
265 (maj . , maj7-modifier)
266 (sus . , sus-modifier)
270 ;; canonical 13 chord.
271 (define the-canonical-chord
277 (ly:make-pitch 1 (- n 8) (nca n))
278 (ly:make-pitch 0 (- n 1) (nca n))))
281 (define (stack-thirds upper-step base)
282 "Stack thirds listed in BASE until we reach UPPER-STEP. Add
283 UPPER-STEP separately."
286 ((> (ly:pitch-steps upper-step) (ly:pitch-steps (car base)))
287 (cons (car base) (stack-thirds upper-step (cdr base))))
288 ((<= (ly:pitch-steps upper-step) (ly:pitch-steps (car base)))