Led Zeppelin, "Nobody's Fault but Mine"
I realize I'm a little late with this observation, since the most recent fossil in the evolutionary chain of the song was unearthed by Chris Cornell and friends in 1994 and the oldest came out of the 1920s. But this morning I realized that I a) had a song in my head and b) couldn't tell if it was "Nobody's Fault but Mine" or "Spoonman." I decided I'd lump those two songs together on the Musical Ripoff jukebox despite their obvious differences—there's just an undeniable influence, in my ears anyway.
But then I discovered that Plant and Page weren't the original authors of the song after all. I was delighted to learn the song is actually an old Negro Spiritual catalogued as far back as 1924.
I also learned I've been misinforming people about the origins of "Spoonman." I knew that Chris Cornell wrote the song based on a made-up song/band name from the movie Singles. What I didn't know was that Jeff Ament had indeed implanted meaning into said name. It is, indeed, about a guy who plays spoons (and also likes to cuddle): Artis the Spoonman.
Go figure. Actually, forget the figuring. Just listen and compare and see what you think.