Lots of times, the most familiar version of a song isn't the original version. I'll be posting some of these "covers that you might not have known are covers" on Saturdays.
"Dazed and Confused"
This is one of several songs that Jimmy Page/Led Zeppelin extensively rewrote and then claimed complete songwriting credit for. Their version is definitive -- Page was genius, even if he was a song thief -- but it's obviously the same song, and Jake Holmes never received a penny from Led Zeppelin for it.
Familiar version: Led Zeppelin (1968)
Original version: Jake Holmes (1967)
Led Zeppelin (a 1969 live version)
Jake Holmes (Page/Zeppelin are incomparable, but I really like this too.)