Re: Tangled up in Lilypond syntax

[Aaron Hill]

On 2019-03-27 3:35 pm, Flaming Hakama by Elaine wrote:
> > ---------- Forwarded message ----------
> > From: Kieren MacMillan <address@hidden>
> > To: Guy Stalnaker <address@hidden>
> > Cc: Tim Slattery <address@hidden>, Lilypond-User Mailing List <
> > address@hidden>
> > Date: Tue, 26 Mar 2019 15:16:03 -0400
> > Subject: Re: Tangled up in Lilypond syntax
> > Hi Guy,
> >
> > > While I don't use \relative
> >
> > Good choice.  =)
>
> The issue is not \relative, per se.  I wish people would stop maligning
> it.   Although I'm sure this commentary is all in good fun.
> The issue is not using it correctly.

I tend to think of something like \relative to be a lower-level 
construct, intended to be used as close as possible to the pitches in 
question.  Since I try to keep things organized in variables where 
content and structure are not intermixed, \relative never appears at a 
higher-level scope in my work.

The only time I have to be careful with \relative is when using \tagged 
expressions:

%%%%
melody = \relative c' {
  | c4 d \tag #'varIA { e2 }
         \tag #'varIB { e8 f g4 }
  | c4 d c2
}
%%%%

I employ this pattern as often melody lines will vary from stanza to 
stanza, but I wish to avoid unnecessary duplication.  The intention is 
that only one of the variations will be active.  However, I have to 
remember that \relative will apply before tagged music is removed.  (The 
corresponding \keepWithTag occurs at the Score level in my usage.)  That 
means the g4 ending the second variation will force the following c4 up 
an octave compared to the initial c4.  Of course, this behavior is 
actually a good thing, as it ensures the music is always interpreted 
consistently, regardless of the presence or absence of tagged 
expressions.

But it has on occasion surprised me when I forgot to compensate for the 
shifting octave.  And more often than not, it is just plain user error 
where I intended to type a comma and typed an apostrophe.  Always fun 
watching your melody lines run off the edge of the paper.  ;-)

-- Aaron Hill