Patrick Karl <[email protected]> writes:
> I'm having a problem trying to learn how to use tags. The following snippet:
>
> \version "2.14.2"
> music = \relative c' {
> \tag #' low {c}
> \tag #' high {c'}
> d e f g a b c
> }
>
> \score {\new Staff { \keepWithTag #'low \music }
> \layout { }
> }
>
> \score {\new Staff { \keepWithTag #'high \music }
> \layout { }
> }
>
> should produce IMHO two c major scales, the first one starting at
> middle c, and the 2nd one starting at one octave above middle c.
> However, there is a problem with the first scale, namely, the first
> note is middle c, but the rest of the scale is shifted up an octave.
> It almost looks like the c' in the expression tagged "high" has had an
> effect on the score containing \keepWithTag #'low.
Sure. \relative is a music function turning relative music into
absolute music. When it does that, both tagged expressions are still in
the music.
> If I switch the two lines, containing \tag, then both scales are
> identical, both starting one octave above middle c. Again, it looks
> like the c' tagged "high" has an effect on the score containing
> \keepWithTag #'low.
>
> Should that happen?
Most definitely. Compare with
\version "2.14.2"
music = {
\tag #' low {c}
\tag #' high {c'}
d e f g a b c
}
\score {\new Staff { \relative c' \keepWithTag #'low \music }
\layout { }
}
\score {\new Staff { \relative c' \keepWithTag #'high \music }
\layout { }
}
Here \relative is run _after_ removing tags, and consequently the output
is as you would have expected.
--
David Kastrup
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