Back in the 70s and 80s (mostly, the 80s), we used call them "guilty pleasure songs".
I'm not sure if I want to "out myself", but I have been a hard rock/heavy metal guy for most of my playing days, except for the fact I played in a second band (when the main band was starting to get some real traction) which played Motown and R&B (I always hid my hair and dressed in a sports coat and slacks with a collared shirt).
Also during those days, it was "fashionable" for bass players to do a rather elongated solo (the rest of the band would leave the stage for some kind of "comfort stop") and because I listened to a lot of classical music (and still do), I used to work the 1812 Overture and Eine Kleine Nachtmusik into my solo.
I guess today, people would be most surprised to hear me break into a little Chattanooga Cho-Choo or I've Got A Gal in Kalamazoo. Big bands was about the most modern music grandma and grandpa listened to around the house.