Whereas I thought, for years, that Lunatic Fringe was a Pink Floyd song. 
I used to think that “Rescue Me” was sung by Aretha Franklin, not Fontella Bass. The confusion probably arose from an early 1990s Pizza Hut commercial featuring Aretha, who sang “Deliver Me” to the tune of Bass’s “Rescue Me.”
John Cafferty & The Beaver Brown Band were Bruce Springsteen imitators. Listen to “On the Dark Side”.
Joey Gregorash was probably never known outside of Canada but his song “Jodie” sure sounded like CCR.
The first time I heard **Dire Straits **Sultans of Swing, I was convinced it was a new **Bob Dylan **track.
How do you not know what Jaret Reddick sounds like? He’s the voice of Chuck E. Cheese!
Speaking of Bowling For Soup, the first time my wife heard “Flavor of the Weak” by American Hi-Fi, she could have sworn they were covering BFS, but BFS has not to my knowledge ever performed that song.