1858 P. L. Simmonds 255/1 Music-folio, Music-wrapper, a case or book for holding loose music.
1895 Spring & Summer 247/1 Music Folio, imitation leather, spring back.
1913 22 Feb. 47 (advt.) If you are weary of expending money for unsatisfactorily-arranged flimsy ‘music folios’, join the Scribner Music Club.