+LY_DEFINE (ly_book_add_score_x, "ly:book-add-score!",
+ 2, 0, 0, (SCM book_smob, SCM score),
+ "Add @var{score} to @var{book-smob} score list.")
+{
+ LY_ASSERT_SMOB (Book, book_smob, 1);
+ Book *book = unsmob_book (book_smob);
+ book->add_score (score);
+ return SCM_UNSPECIFIED;
+}