Re: beam slope

[Janek Warchoł]

Hi Helge,

On Sat, Feb 25, 2012 at 6:28 AM, Helge Kruse <address@hidden> wrote:
> Lilypond calculates a very nice slope for the beams. But it fails when I add 
> a staff change. What's wrong with my Lilypond code?

You have to explicitely tell lily that you want a kneed beam.  Set
stem directions or use "directional voices":

\version "2.14.2"

instrumentDrei = \relative c' {
 \clef treble
 \stemUp
 r4 \times 4/6 { c'16 g e c g e }
 g,4\times 4/6 { \stemDown c''16 g e c \change Staff=four \stemUp g e
} \change Staff=three |
}

instrumentVier = \relative c' {
 \clef bass
 \stemDown
 \times 4/6 { g,16 e' g c e g } c4
 \times 4/6 { \voiceOne g,,16 e' g \change Staff=three \voiceTwo c e g
} \voiceOne c4 \change Staff=four
}

\score {
 \new PianoStaff <<
 \new Staff=three { << \instrumentDrei >> }
 \new Staff=four { << \instrumentVier >> }
 >>
}

Usually it's better to use \voiceOne, \voiceTwo etc. rather than \stemUp/Down.

The results might not be perfect; cross-staff beams aren't extremely
well supported in Lily now.

HTH,
Janek