Lowest and highest pitch as chord: Difference between revisions

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-This code returns the lowest and the highest pitch of a music expression as chord.
+Takes <code>MUSIC</code> and returns sequential music, simultaneous music or an event-chord
+with duration <code>DURATION</code>, relying on the type M provides.
+The optional <code>PROC</code>, supposed to be <code>{first}</code> or <code>{last}</code>, may be used to get the bottom or top note only.
-The duration of the chord can be chosen arbitrarily as input parameter.
+<lilypond version="2.26.0" >
-You can easily change the chord to a fixed duration. You can even chose different durations for the pitches in the chord.
+#(define (make-note-event pitch duration)
+  "Takes PITCH and DURATION and returns a NoteEvent."
-<lilypond version="2.26.0" >
+  (make-music
+   'NoteEvent
+   'duration duration
+   'pitch pitch))
+#(define (bottom-top-notes music duration)
+  "Takes MUSIC and returns lowest and highest note each with duration DURATION
+as a plain list."
+  (let* ((all-pitches (music-pitches music))
+         (sorted-pitches (sort all-pitches ly:pitch<?)))
+    (map
+      (lambda (pitch) (make-note-event pitch duration))
+      (list (car sorted-pitches) (last sorted-pitches)))))
-%% This snippets returns the lowest and the highest pitch
+extrema =
-%% of a music expression als chord
+#(define-music-function (proc m music duration)
-%% the duration of the chord is passed as argument
+  ((procedure? identity) ly:music? ly:music? ly:duration?)
+"Takes MUSIC and returns sequential music, simultaneous music or an event-chord
+with duration DURATION, relying on the type M provides.
+The optional PROC, supposed to be @code{first} or @code{last}, may be used to
+get the bottom or top note only."
+  (ly:music-set-property! m 'elements
+    (ensure-list (proc (bottom-top-notes music duration))))
+  m)
+%%%%%%%%%%%%
+%% EXAMPLES
+%%%%%%%%%%%%
-myambitus =
+testMus = \relative { d' e fis g a b cis }
-#(define-music-function (mus dur)(ly:music? ly:duration?)
-   (let*
+{ \extrema {} \testMus 4 }
-    (
+%% Below, preceed with \new Staff to avoid implicit creation of two staves
-      (alle-pitches
+{ \extrema <<>> \testMus 4 }
-       (let loop ((mus mus) (pitches '()))
+{ \extrema <> \testMus 4 }
-         (let ((p  (ly:music-property mus 'pitch)))
-           (if (ly:pitch? p)
-               (cons p pitches)
-               (let ((elt (ly:music-property mus 'element)))
-                 (fold loop
-                       (if (ly:music? elt)
-                           (loop elt pitches)
-                           pitches)
-                       (ly:music-property mus 'elements)))))))
-      (alle-sortiert (sort alle-pitches ly:pitch<?))
-      (tief (car alle-sortiert))
-      (hoch (car (reverse alle-sortiert)))
-      )
-    ;     (display tief )(display hoch)
-    ;     (write-me "alle pitches----> " (list? alle-pitches))
-    (make-music
-     'EventChord 'elements
-     (list
-      (make-music
-       'NoteEvent
-       'duration
-       dur
-       'pitch
-       tief)
-      (make-music
-       'NoteEvent
-       'pitch
-       hoch
-       'duration
-       dur)))
-    ))
-mymus = \relative { c' c f,, }
+%% Get only bottom or top note
-{ \clef bass \myambitus \mymus #(ly:make-duration 0) }
+{ \extrema #first {} \testMus 4 }
-{ \clef bass \myambitus \transpose c e \mymus 2. }
+{ \extrema #last {} \testMus 4 }</lilypond>
-</lilypond>
 [[Category:Pitches]]
 [[Category:Scheme]]