This is a variation on issue #34 (grace note synchronization) where \stemNeutral gets ignored in one staff if there's a grace note in the other.
%%% \version "2.25.18" rightHand = \relative { c'1 | \grace { c8 } c2 } leftHand = \relative { \clef bass \stemDown f,2 f | % \grace { s8 } % <-- uncomment to fix the problem \stemNeutral f,8\noBeam f'' c' d } \score { \new PianoStaff << \new Staff \rightHand \new Staff \leftHand >> } %%% The \stemNeutral in the left hand gets ignored unless you use a "spacer grace note". This is probably not different enough to post back to the #34 issues page (which has a lot of discussion) but I thought I'd post it here as it took me a little while to figure out. -- Knute Snortum