Music

Could one of the more musically literate people here maybe explain what I'm describing in theory terms?

Well, it’s certainly a number of things.

But one of the most noticeable differences I’ve heard is that a lot of the stuff you mentioned does not shy away from using authentic cadences, whereas the American mainstream (in particular; I just don’t know how things have been in Europe or anything like that) now finds that... a little sugar sweet, shall we say? Not to be used as often as it used to be, at least. Some songs over the past few decades have avoided using leading tones almost pathologically (often using suspensions or stacked chords to give the mere impression of a V, or leaning on some other kind of cadence entirely).

The emphasis on pentatonic colors is another big part of that “sweet” sound that a lot of music avoids now, sure.

And now that I’ve spoken in generalities, there are plenty of exceptions to these trends, and they could just reverse at any time if that’s what people wanted. In fact, I pay enough not-attention to what’s new that it may have already reversed and I just haven’t noticed.

In summary: in a very general way, Japanese songwriters and composers are using the sort of traditional harmony you can find in a 100-year-old textbook more than American songwriters and composers are. That’s not to say that new developments in music are lost on any group in particular, or that any group in particular has thrown out the old rulebooks, though.