Every professor has their own way to deal with students who fall asleep in their class, be that simply ignoring them or doing something outlandish to get their attention.
This professor chooses the latter and wakes his students up by casually getting as close to them as possible during his lecture and then BELTING various “emo” songs in their faces until they wake up.
It seems these students at have a pretty great relationship with him and can laugh it off.
