When it comes to digitizing large theater and music program collections, it is well-established that a library can digitize anything before 1923, and that if there are no copyright notices on them, can digitize anything before 1978. But if there are multiple "copyrightable" elements in the works (advertisements, photos, actor biographies, illustrations, etc.) is it okay to digitize them?
This is a complex issue (although not nearly as complex as assessing a library wing full of dramatic and musical works). To unpack this, I will take advantage of a form suggested by the topic: the opera libretto.
[Cue overture…]
ALTO: Can works with no copyright notice before 1978 be safely digitized?