+satb-define-if-unused =
+#(define-void-function (parser location syms) (symbol-list?)
+ (for-each
+ (lambda (sym)
+ (if (null? (ly:parser-lookup parser sym))
+ (ly:parser-define! parser sym *unspecified*)))
+ syms))
+
+\satb-define-if-unused
+ #'(
+ DescantMusic
+ SopranoMusic
+ AltoMusic
+ TenorMusic
+ BassMusic
+ )
+
+satb-AllChoirMusic = <<
+ \DescantMusic
+ \SopranoMusic
+ \AltoMusic
+ \TenorMusic
+ \BassMusic
+>>
+
+#(define satb-spacers (skip-of-length satb-AllChoirMusic))
+