+ void add_score (SCM);
+ void add_performance (SCM);
+
+ SCM performances () const;
+ SCM systems ();
+ SCM pages ();
+ SCM get_system_specs ();
+
+
+ Stencil book_title ();
+ Stencil score_title (SCM);
+
+ void classic_output (SCM output_channel);
+ void output (SCM output_channel);