Why the bleep would you have background music in a video in which someone is explaining something (in speech)? Do you, video maker, *want* people to get distracted and unable to concentrate on what you're actually saying?
(without the music this would have been an interesting video in which a mathematician explained some math, I think. The music wasn't loud but very irritating and distracting so I didn't remember much of what was said. But at one moment she said "where do we even start?" and just then there was a cute cat so I said "start with petting the cat" but of course there was only one-way communication and she didn't hear me. Or get the idea herself.)
