Theater, music, and literature tend to appeal to a "higher" class of people than film, comedy, and speaches. This higher class might care more and be more knowledgable about the subtelties of attribution.
No, I think you're creating a class distinction where it's completely unnecessary (and a weird thought to even have, I think).
Theater, music (I'll assume we're not talking about "popular" music, but something more like classical music here), and literature tend to have known authors, and tend to have a wide variety of performances. (Although literature is weird to include in this list, I think).
Film, comedy (since it's differentiated from theater and film here, let's say stand-up comedy) and speeches have known performers. Authors in film are sometimes relatively well-known, but I think attributions to actors rather than characters in films aren't that common.
Theater, music (I'll assume we're not talking about "popular" music, but something more like classical music here), and literature tend to have known authors, and tend to have a wide variety of performances. (Although literature is weird to include in this list, I think).
Film, comedy (since it's differentiated from theater and film here, let's say stand-up comedy) and speeches have known performers. Authors in film are sometimes relatively well-known, but I think attributions to actors rather than characters in films aren't that common.