generalize the idea in snippet 372

[Wilbert Berendsen]

Hi,

based on the idea of http://lsr.dsi.unimi.it/LSR/Item?id=372 I created this 
small function that creates a filtering function to remove certain event types 
from a music expression:

#(define-public (define-music-event-filter names)
  (define-music-function (parser location music) (ly:music?)
    (music-filter
      (lambda (event) (not (member (ly:music-property event 'name) names)))
      music)))

This function can then be used to create a custom filtering function like 
this:

filterdynamics = #(define-music-event-filter 
  '(AbsoluteDynamicEvent CrescendoEvent DecrescendoEvent TextScriptEvent))

music = \relative c' {
  c\p\< d e f g\ff
}

\score { \new Staff \filterdynamics \music }

This makes using this idea easier: you don't have to copy and re-edit the 
filterOneEvent function each time. Filtering music expressions is useful to 
e.g. create a piano reduction from orchestral parts.

best regards,
Wilbert Berendsen

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Frescobaldi, LilyPond editor for KDE: http://www.frescobaldi.org/