Re: Guitar notation - scheme function for slurs with markup

[Lukas-Fabian Moser]

Hi Stefan,

Am 29.05.22 um 22:42 schrieb Stefan E. Mueller:
> I am not sure yet what the difference between a scheme-function and a
> music-function is (the second example seems to work whichever definition
> is chosen).
A music function must return music, a scheme function can return more 
general expressions (for instance, a new function or a list of symbols).
> The "-" dash in my case added an (unwanted) accentuation to
> the first note, I get the slur with the markup without the accent only if
> I remove it (not sure what it is supposed to do - manual says it is a 
> required
> named direction indicator, but in my version 2.22.1 it doesn't work 
> like that).

Ah, I thought you wanted the accent. :-)

Both the - and ^ symbols have various meanings; it's important to read 
them in order.

Add articulation with neutral direction/up-facing/down-facing: -!, ^!, 
_! (here I use ! = staccatissimo as an articulation, but ( = slur, ^ = 
marcato and - = tenuto are other examples)

If you just want a slur that should have its direction forced upwards, 
just write ^(

> I thought the function-constructs were merely doing variable
> substitutions, but it seems there is more to this. Because now I have the
> problem how to describe several hammer-ons in a row with a function, like
> this:
>
> \new Staff {
> e''8^(^\markup {\halign #-1.5 ho} f''8)^\markup {\halign #-1.5 ho} g''\8)
> }
>
> Ideally, I'd like to be able to write this like
>
> e''8 \ho f''8 \ho g''8
>
> (with the corresponding closing brackets also provided by the function,
> but it may be that this is not possible).

I assume you want another slur to start on the f''? Then maybe something 
like this:

\version "2.22"

ho =
#(define-music-function (spacing music) ((number? -1.5) ly:music?)
   #{
     <>^(^\markup {\halign #spacing ho}
     #music
     <>)
   #})

\new Staff {
  e''8 \ho f''8 \ho g''8 a''
}

Lukas