Fascinating and thoughtfully explained premises. My experience as a young person and as an older adult ("mean" age 72) is consistent with the findings described here.

I think there's another dimension at work here. It's my belief that we use entertainment (music, movies, books) as a way to achieve emotional homeostasis. We reach this homeostasis not by tamping down emotions (as with a sedative) but by arousing them and then effectuating a sense of control over them (through what I believe is a fairly complex and variable process).

The difference between the way young people seek homeostasis and old people do so (including type of music--or type of movie or book, e.g. horror films are perhaps more popular among people when they're young than the same people when they're older) may be a consequence of the sort of initial imbalance that the individual is experiencing.