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'{