Re: [GLISS] non-timed or non-musical events "z" "y"

[Joseph Rushton Wakeling]

On 13/09/12 08:11, David Kastrup wrote:
> If it does, so does
>
> << c'1 { s4 s\< s2 s\! } >>

Stepping back from syntax for a second, the problem with the above (as currently 
implemented) is that the spacing will not produce correct output from a visual 
engraving point of view.  This applies also to articulations, ornamentations, 
etc. which do not fall exactly on the note.

Consider e.g.

    c'4 c'4\turn << { c'2 } { s4 s4^\turn } >>

Now, what you _want_ here is that the spacing for the final c'2 to be such that 
it's clear that the \turn falls on the second quarter.  That means that the 
spacing of the c'2 probably needs to be larger than it would be otherwise, and 
the \turn needs to fall halfway through that space.

What you actually _get_ is that the spacing of c'2 is entirely unaffected, and 
the \turn falls in a location just to the right of the note-stem which makes it 
look as if it's been accidentally placed a bit off.

AFAICS this happens because Lilypond considers "skip" elements s to be 
irrelevant for spacing purposes.

The same applies to your example with the crescendo starting on the 2nd beat of 
the c'1.  You don't get sufficient horizontal spacing following the note to be 
able to appreciate the nuances of the hairpin's placement: in practice, it would 
most likely be read as starting on the note itself.

Further, the quarter-beat positions do not fall evenly in that horizontal space, 
so if you have e.g. a \< \> on the same note, it may look like one is longer 
than the other.  Try e.g.:

    << { c'1 } { s4 s\< s\> s\< s\! } >>

... where each of the hairpins should last one quarter-beat, but actually they 
are all of different horizontal widths, and the \> could easily be mistaken for 
an accent.

So to me, the problem is not with the existing syntax per se, but the fact that 
the existing syntax _doesn't produce the desired output_ and needs lots of 
complicated tweaks to get right.