--- /dev/null
+\version "2.16.0"
+\header {
+ texidoc = "The prefix of additional chord pitches can be tuned with
+@code{additionalPitchPrefix}."
+}
+
+\new ChordNames {
+ <c e g d'> % add9
+ \set additionalPitchPrefix = #"add"
+ <c e g d'> % add9
+}