-(define-public (add-music-fonts node name family design-size-list factor)
- "Add fonts to NODE. DESIGN-SIZE-LIST is a list of numbers."
+(define-public (add-music-fonts node name family design-size-alist factor)
+ "Set up music fonts.
+
+Arguments:
+@itemize
+@item
+@var{node} is the font tree to modify.
+
+@item
+@var{name} is the basename for the music font.
+@file{@var{name}-<designsize>.otf} should be the music font,
+@file{@var{name}-brace.otf} should have piano braces.
+
+@item
+@var{family} is the family name of the music font.
+
+@item
+@var{design-size-alist} is a list of @code{(rounded . designsize)}.
+@code{rounded} is a suffix for font filenames, while @code{designsize}
+should be the actual design size. The latter is used for text fonts
+loaded through pango/@/fontconfig.
+
+@item
+@var{factor} is a size factor relative to the default size that is being
+used. This is used to select the proper design size for the text fonts.
+@end itemize"