What normally happens is someplace like Sony Music or whoever holds the copyright will put a copyright claim. The video plays but the copyright holder receives any money from the number of views. In some rare cases, some bands (The Eagles and Fleetwood Mac for example) will put an outright block on the video, and if you're The Cars, they'll ask YouTube to give you a copyright strike. 3 copyright strikes on your account, and your YouTube account is permanently disabled.
I've uploaded some videos of my bass playing of Rush songs, and Rush just put a copyright claim. You can still see and hear my videos, Rush gets the $.10. And since they're retired, they need all the $.10 they can get!