4 Beams can be typeset over fixed distance aligned staves, beam
5 beautification doesn't really work, but knees do. Beams should be
6 behave well, wherever the switching point is.
11 \context Staff=one \notes\relative c'{
12 \stemUp [c8 c \translator Staff=two \stemUp c c]
15 \stemDown [c8 c \translator Staff=two \stemUp c c]
17 \stemDown [c8 c \translator Staff=one \stemDown c c]
20 \stemUp [c8 c \translator Staff=one \stemDown c c]
23 \context Staff=two \notes\relative c'{