1\header {
2
3  texidoc = "Stem directions for notes on the middle staff line are
4  determined by the directions of their neighbors."
5
6}
7
8\version "2.19.21"
9\relative \new Voice \with {
10     \consists "Melody_engraver"
11     \override Stem.neutral-direction = #'()
12} {
13  c''4 b c b
14  c c c c
15  b a b a
16}
17
18
19