+/*
+ Note_head contains the code for printing note heads.
+
+ Ledger lines:
+
+ It also contains the ledger lines, for historical reasons. Ledger
+ lines are somewhat of a PITA. In some cases, they take up no space, in
+ some cases they don't:
+
+ DO take space:
+
+ - when ledgered notes are juxtaposed: there should be some white
+ space between the ledger lines.
+
+ - when accidentals are near: the accidentals should not be on the
+ ledger lines
+
+ [both tips by Heinz Stolba from Universal Edition].
+
+ DO NOT take space into account:
+
+ - for basically everything else, e.g. swapping ledgered notes on
+ clustered chords, spacing between ledgered and unledgered notes.
+
+ TODO: fix this. It is not feasible to have a special grob for
+ ledgers, since you basically don't know if there will be ledgers,
+ unless you know at interpretation phase already 1. the Y-position,
+ 2. the number of staff lines. It's not yet specced when both pieces
+ of information are there, so for now, it is probably better to build
+ special support for ledgers into the accidental and separation-item
+ code.
+
+ (Besides a separate ledger seems overkill. For what else would
+ it be useful?)
+
+*/
+
+#include "staff-symbol-referencer.hh"