\layout { \context { \Score skipBars = ##t \markLengthOn } }
{ \tempo "Tempo" 4=120 R1*4 \mark\default } The MMR should only stretch to the minimum length necessary to accommodate the MetronomeMark. This leads to very ugly results with long MetronomeMarks, including sometimes stretching measures beyond the page margins (even if the text itself fits within the margins). It also leads to ugly results when a system contains multiple MMRs, as one is too wide and the other too narrow. I have not found an obvious way to tweak this behavior.