Imported Upstream version 2.19.45

[lilypond.git] / Documentation / snippets / new / replacing-default-midi-instrument-equalization.ly

diff --git a/Documentation/snippets/new/replacing-default-midi-instrument-equalization.ly b/Documentation/snippets/new/replacing-default-midi-instrument-equalization.ly
new file mode 100644 (file)
index 0000000..dbe4e94
--- /dev/null
+++ b/Documentation/snippets/new/replacing-default-midi-instrument-equalization.ly
@@ -0,0 +1,59 @@
+\version "2.19.21"
+
+\header {
+
+  lsrtags = "scheme-language, midi"
+
+  texidoc = "The default MIDI instrument equalizer can be replaced by
+  setting the @code{instrumentEqualizer} property in the @code{Score}
+  context to a user-defined Scheme procedure that uses a MIDI instrument
+  name as its argument along with a pair of fractions indicating the
+  minimum and maximum volumes respectively to be applied to that
+  specific instrument.
+
+  The following example sets the minimum and maximum volumes for flute
+  and clarinet respectively."
+
+  doctitle = "Replacing default MIDI instrument equalization"
+}
+
+#(define my-instrument-equalizer-alist '())
+
+#(set! my-instrument-equalizer-alist
+  (append
+    '(
+      ("flute" . (0.7 . 0.9))
+      ("clarinet" . (0.3 . 0.6)))
+    my-instrument-equalizer-alist))
+
+#(define (my-instrument-equalizer s)
+  (let ((entry (assoc s my-instrument-equalizer-alist)))
+    (if entry
+      (cdr entry))))
+
+\score {
+  <<
+    \new Staff {
+      \key g \major
+      \time 2/2
+      \set Score.instrumentEqualizer = #my-instrument-equalizer
+      \set Staff.midiInstrument = #"flute"
+      \new Voice \relative {
+        r2 g''\mp g fis~
+        4 g8 fis e2~
+        4 d8 cis d2
+      }
+    }
+    \new Staff {
+      \key g \major
+      \set Staff.midiInstrument = #"clarinet"
+      \new Voice \relative {
+        b'1\p a2. b8 a
+        g2. fis8 e
+        fis2 r
+      }
+    }
+  >>
+  \layout { }
+  \midi {  }
+}