Issue 2270 in lilypond: Feature request: cross-staff chords

[lilypond]

Status: Accepted
Owner: ----
Labels: Type-Enhancement

New issue 2270 by address@hidden: Feature request: cross-staff chords
http://code.google.com/p/lilypond/issues/detail?id=2270

By Pavel Roskin:
http://lists.gnu.org/archive/html/bug-lilypond/2012-01/msg01274.html

In my opinion, Lilypond should be able to support chords with noteheads on  
different staves. This is especially important within staff groups for  
keyboard instruments.

Lilypond can already move a voice from one staff to another. It can connect  
notes on different staves with beams. Yet it doesn't allow notes from one  
voice to be on different staves at the same moment.

Lilypond supports cross-staff stems, which provides a workaround and thus  
acknowledges the need to have cross-staff chords.

The problem with the cross-staff stems is that there is no reliable way to  
ensure that they would reach all the noteheads unless the distance between  
staves is fixed. Fixing the distance between staves requires such hacks as  
negative padding. Lilypond should be free to choose the distance between  
staves for the best layout and adjust the cross-staff stems to look  
correctly.

It is possible to use overlapping stems to guard against stem  
discontinuity. However, overlapping parts of stems may look darker than  
non-overlapping parts dependent on the anti-aliasing algorithm used to  
display them.

But it's not just about stems. Even whole notes could benefit from being in  
a cross-staff chord. It would make it easier to connect those notes to  
other notes from the same voice.

The most natural syntax would be to allow \change inside chords:

\new PianoStaff <<
  \new Staff = right { <c' \change Staff=left c>4 }
  \new Staff = left { \clef bass s4 }