An artist?
A song?
An album?
Lyrics?

For example... just last night I learned that one of my favorite songs, "Alive With the Glory of Love" is actually about the Holocaust.

Also, I learned a few years ago that the lyrics aren't "hey josie" but "hey jealousy" by the Gin Blossoms. (Yes, I now know that's the NAME of the song)

Let's Get it Started is actually Let's Get Retarded.

"Turning Japanese" (The Vapors) is about a guy squinting his eyes like an asian when he's masterbating too hard

"We Are Young" (Fun.) is a creepy stalker song about a physically abusive boyfriend watching his ex girlfriend across the bar, waiting for her to pass out so he can carry her home and probably rape her

I assume most people know this one, but "Long May You Run" (Neil Young) is about his car

"Closing Time" (Semisonic) is a metaphor for the birth of his child (There's some lines of it talking about beer or whisky, so I don't think it's ONLY about the birth, but it's kind of a double meaning with lines that are clues like "Closing time, this room won’t be open till your brothers or your sisters come")

"MMMbop" by Hanson is a deep song about aging and passage of time in relationships

A 90's singer once did a sexploitaton film when her career was in a downward spiral.

"Starry Starry Night" is a song about Van Gogh.