I'm not talking about a song you heard for the first time and thought it must be a certain artist only to be quickly corrected (e.g., people thinking "Sultans of Swing" was Dylan when Dire Straits first started getting radio play). I'm talking about songs that, for years, you believed were sung by Artist B but they were really performed by Artist A. I'll start. Until only a few years ago, I thought "Owner of a Lonely Heart" was performed by the Police. In my defense, I was never a even a casual fan of the Police or Yes (or any prog-ish bands in the late 70's-early 80's for that matter). I'm sure there are others like me. Let's hear 'em.
Not I, but a friend is convinced that the song "The Heat Is On" is by Huey Lewis and not the dead guy from the Eagles.
When Napster was a thing, I eagerly went looking for music by The B-52's, since their albums (aside from the first two and Cosmic Thing) were hard to find in my small town and I didn't really know what else they might have released. I stumbled on a song called Time Warp, which certainly sounded like something they might have come up with when I listened to it. It was several years before I finally saw the Rocky Horror Picture Show and realized that it wasn't in fact by The B-52's...
I also had a friend (a non-Springsteen fan) who was shocked to learn that "On the Dark Side" was John Cafferty.
I know this is absolutely dumb, but when I was a kid, I thought that Dire Straits and Ment at Work were the same thing…
Not a song and not by me, but again thanks to Napster, Marshall Tucker Band often getting confused with Allman Brothers.
I got a lot of grief a long time ago on here for mentioning I used to think The Heat Is On was by Queen, when I was a child
I don't think it was for years, but I originally mistook Genesis's Follow You Follow Me for Seals & Crofts.
For years whenever I'd hear the Hondells hit. "Little Honda" on the oldies station I assumed it was the Beach Boys. Boy did I have egg on my face when I discovered how wrong I was.
Thanks to Napster I thought Lemon Tree by Fool's Garden was a Blind Melon song. I thought this for many, many years until I tried to find out why it wasn't on any of their albums.