Sure, I agree. Some people have noted the similarity between “Communication Breakdown” and Eddie Cochran’s “Nervous Breakdown”, and similarities between “How Many More Times” and Howlin Wolf’s “How Many More Years” and “Smokestack Lightnin” both (lyrics from one, riff from another.) But again, those songs were changed more than enough to warrant them being considered Led Zep compositions. I think they later gave Wolf partial credit (probably because they’d already been sued for “The Lemon Song” and “Bring It On Home.”)
[edit: “ten notes in a song that’s more than five minutes long” well. . . the first part of “Amazing Grace” is ten notes, and is pretty distinctive, if someone used it people would immediately notice, so the actual number of notes might not always be the issue. The fade-out refrain to “Hey Jude” is ten notes, though one part repeats, and that song is about five minutes-- you couldn’t get away with stealing that unattributed.]
