5 Markings can be attached to (invisible) barlines.
9 \paper { raggedright = ##t }
11 onestaff = \new Staff\relative c'' {
12 \set Staff.instr = instr
13 \set Staff.instrument = instrument \mark "B"
14 c1 \mark "A" \break c2 c2 \break
17 grstaff = \relative c''
18 \context GrandStaff <<
21 \set Staff.instr = instr
23 \mark "B" \break c1 \mark "A" c2 }