In my personal view, you can use this approach for short introductions or summaries. For serious content which requires more concentration, this is not a useful implementation.
What are your thoughts about this?
I would personally sometimes like to be able to watch without music. Especially at grumpy times. :-]
But at other times I really respect the creator more for daring to pick something. I myself like things like the Geowizard approach with lowkey midi-sounding stuff. For course content generally the volume or sound dynamic matters more than style in a lot of ways.
Still, to me the unspoken truth in these questions is...we could be allowed to offer both options in one video, but we're not. It's really too bad, considering how many blatantly rude video critic-trolls find their way into e.g. the YouTube comments section.
Good luck...whatever you try at least you asked about it ahead of time. That is, if you are planning on making your own video. If just a general q then yeah it depends.
Also IMO music choice points to creator psychology. If it's a match with my psychology it's even better. If it's not, even worse.
Also (and more plausible), in a "lower information" mood I will stream music in a different tab. Generally each tab's player will have a separate volume control.