In flamenco and bossa-nova guitar music it is quite common to damp some (but not all) strings with the left hand while strumming. The standard notation for this is to have cross-noteheads on the damped strings
and normal noteheads on the strings that should ring.
Lilypond makes it extremely tedious to deal with this relatively common situation. It's easy to have the entire chord drawn with x-noteheads, but much more difficult
to get only some of the notes to have x-noteheads.
For instance, let's say we're notating the strumming of eighth-note open A-minor chords, like so:
\relative c' { <a-0 e'-2 a-3 c-1 e-0>8
<a e' a c e> <a e' a c e> <a e' a c e>
<a e' a c e> <a e' a c e> <a e' a c e> <a e' a c e>
}
So far the music only needs one voice, and it prints in an easy-to-read (for guitarists) stacked notation, with one stem per chord.
But let's say we want every other chord to be partly
damped: strings 2, 3 and 4 have x-noteheads, and strings 1 and 5 have normal noteheads. We don't want any other visible changes to the print representation -- in particular, this is not polyphonic music, so we don't
want up- and down- stems in the same measure, nor notes from any given chord to be horizontally shifted. We just want every other chord to have its middle three noteheads be crosses.
The only way to accomplish this, as far as I can tell,
requires many manual steps for each measure: - split the music _expression_ into two voices - copy the chords into the second voice - delete all the normal-notehead notes from one voice - delete the cross-notehead notes from the other voice
- make the stems and beams in the top voice invisible - turn off note-column collision warnings - in some cases, hack the stem #'length-fraction so that the beam from the lower voice clears the higher.
This is somewhat labor-intensive, and annoying to read (although it can be mitigated a bit with macros). But the
real problems have only just begun. Now that it's been split into two voices, everything you add to the staff begins to have layout issues. Take a look at the fingerings in the two measures above. In the one-voice version, the fingerings
line up nicely, with three above the staff and two below. In the two-voice version, most of the fingerings overlap with other entities, rendering them unreadable.
You'll run into the same kinds of issues with every kind of
annotation, from string numbers and right hand fingerings through accent marks and TextSpanners. The hack to split the chords into multiple voices wreaks havoc with the layout engine as we add more information to the staff.
We could fix this problem by adding another special-case similar to \harmonic for cross-noteheads. But I have a sneaking feeling it wouldn't be the last such special case.
It seems like a better solution would be to provide syntax
support for overriding individual noteheads within a chord to be arbitrary glyphs or stencils -- whatever you can do with noteheads outside of chords, basically.
But I'd take the hack, for now! I'm transcribing a piece
that has many of these partly-damped chords, and I'd love to have a way to annotate them properly.
Thanks,
-steve
p.s. Thank you for this awesome system, by the way.