+ {
+ output_paper_book->add_performance (perf->self_scm ());
+ // Associate the performance with a \header block (if there is
+ // one in effect in the scope of the current score), to make the
+ // header metadata accessible when outputting the performance.
+ if (ly_is_module (score->get_header ()))
+ perf->set_header (score->get_header ());
+ else if (ly_is_module (output_paper_book->header_))
+ perf->set_header (output_paper_book->header_);
+ else if (ly_is_module (output_paper_book->header_0_))
+ perf->set_header (output_paper_book->header_0_);
+ }