Re: stem length in a three voice setting

[Thomas Morley]

Am So., 18. Okt. 2020 um 21:47 Uhr schrieb Kevin Barry <barrykp@gmail.com>:
>
> Hi Bart,
>
> I'm away from my computer so I can't verify what I'm about to say, but I 
> think that once a note is beamed it is actually the beam that controls the 
> lengths of the stems. I think you need to override the Beam's positions 
> property (if memory serves) to accomplish what you want.
>
> Kevin

Yes and no, the Beam is positioned respecting various conditions.
Among them are the values stored in Stem.details (see IR).
Changing those values is at first more try and error work, though I
think one has better chances to find values which could serve for the
whole score.
The override for Beam.positions is static, i.e. every Beam will get
those values and I'm pretty sure the need to change Beam.positions
will occur quite frequently. Alternatively one could always offset
Beam.positions by certain values, though I expect only a little chance
to find values for the whole score.

One needs to try it out...

Here a code with changed Stem.details relying on Aaron's code:

%%%%
\version "2.20.0"

classicalGuitarA = \relative c' {
   \tuplet 3/2 { fis16 g fis } eis8 fis
}
classicalGuitarB = \relative c' {
   \override Stem.details.beamed-extreme-minimum-free-lengths = #'(0.1 0.1 0.1)
   \override Stem.details.beamed-lengths = #'(0.2 1.2 1.3)
   \once \shiftOff
   d8 cis d
}
classicalGuitarC = \relative c {
   d4.
}

{
   \key d \major
   \time 3/8
   \clef "treble_8"
   \voices 1,4,2 <<
     \classicalGuitarA \\
     \classicalGuitarB \\
     \classicalGuitarC
   >>
}
%%%%

Cheers,
  Harm