Everyone knows is a big NO-NO to beat your kids, under any circumstances, it's totally unacceptable, but that's exactly what you first think is happening here as the video starts to play.
However, things change very quickly as your perception of the events takes a turn for the positive and your brain slowly realizes what exactly is going on and where those 'strange' noises are coming from as dad uses his toddler's son back as a mixing deck, drumming out some beats on him while the kid's squeals and giggles of delight work perfectly as some added sound effects.
So in conclusion, it sure looks like a great way to teach a toddler a lesson in 'music' by beating them could be a great idea.
It's pretty much the best instrument ever.
Just don't continue it into adulthood and apply the 'Whiplash' method as you won't win any Oscars for it, more likely a visit from your local law enforcement.