Re: [GLISS] differentiating pre/post/neutral commands

[Joseph Rushton Wakeling]

On 11/09/12 14:15, David Kastrup wrote:
> No.  Just those commands that are not intrinsically attached to a note
> within a voice, like dynamics and phrasings.  Basically those things
> that you'd occasionally attach to <> or s1*0 for lack of something more
> suitable.

In the case of dynamics, you really have 2 cases to cover: first, dynamics that 
coincide exactly with a particular note (the current default case in Lilypond) 
and second, dynamics (and this includes hairpins etc.) that are offset relative 
to a given note.  So, whatever is decided regarding whether the dynamic command 
comes before or after the note, there needs to be some tidy shorthand for 
illustrating the offset; and it needs to be possible to attach more than one 
dynamic indicator to a given note.

Example: consider a half-note where you have a \p dynamic falling on the start 
of the note; a \< hairpin that lasts a quarter-note; an \f dynamic that falls on 
the second quarter of the half-note; and a \> hairpin that falls across the 
remainder of the half-note (i.e. it also lasts a quarter-note).

The most simple way to do this is to add a parallel voice containing,

    s4\p\< s4\f\>  % ... etc.

but in practice you'd probably have to put in place some tricks involving hidden 
quarter-notes in order to get the spacing right.

So in practice you might prefer something like,

    c'2\p\<4 \f\>4

.... i.e. where some dynamic elements can be given a duration.

If you wanted to have e.g. a half-note where a crescendo starts halfway through, 
you might have something like,

    c'2\p4 \<

Or you might have a note where the dynamic changes suddenly in the middle:

    c'2\p4 \f

(These particular syntax ideas may be unworkable in practice, but you get the 
idea -- dynamic events [and possibly some articulations too] can have length in 
their own right, and we need a way to indicate this; and horizontal spacing of 
dynamic elements will need to take these factors into account.)