ghost voiceconsisting of spacers and durations only (e.g. c2 d e ==> s2 s s). This is very useful for writing simultaneous voice parts where one contains pitches, another dynamics, a third fingering instructions ... This can easily be used to print a score with or without fingerings or other attributes! The ghost music can be written to the log with
\displayLilyMusic \ghostMusic followed by the music to be transformed.