Re: the note in removed tag still affects the following pitch

[Thomas Morley]

2014-12-22 20:05 GMT+01:00 Jinsong Zhao <address@hidden>:
> Hi there,
>
> In the following snippet, \removeWithTag #'b have a different effect with
> commenting the line of \tag #'b. It seems that the pitch after \tag #'b also
> affected by the removed tagged expression.
>
> \version "2.19.15"
>
> music = \relative c'' {
>   \clef "treble"
>   \key ees \major
>   \time 4/4
>   \tempo 4 = 90
>     ees4 ees'2.
>          \tag #'b {aes'2.}
>     ees,4 ees'2.
>     aes,1
> }
>
> \new Voice {
>   \removeWithTag #'b
>   \music
> }
>
> Any suggestion or comment will be really appreciated.
>
> Best regards,
> Jinsong

See:

http://www.lilypond.org/doc/v2.19/Documentation/notation/different-editions-from-one-source#using-tags

"
Known issues and warnings

Calling \relative on a music expression obtained by filtering music
through \keepWithTag or \removeWithTag might cause the octave
relations to change, as only the pitches actually remaining in the
filtered expression will be considered. Applying \relative first,
before \keepWithTag or \removeWithTag, avoids this danger as \relative
then acts on all the pitches as-input.
"

Your example should read:

music = {
  \clef "treble"
  \key ees \major
  \time 4/4
  \tempo 4 = 90
    ees4 ees'2.
         \tag #'b { aes'2.^"tagged" }
    ees,4 ees'2.
    aes,1
}

\new Voice {
  \relative c''
  \removeWithTag #'b
  \music
}

HTH,
  Harm