Why do you think the kind of atmospheric music common in the music scene today was non-existent 20 years ago?

I'm kind of talking like dream pop kind of stuff, where they focus on sort of melding everything together. I mean, I've always kinda wanted to make that kind of...abstract art kind of stuff, where you add a bunch of different things together that create something greater than the some of their parts, and nothing's really taking the lead, it's just a meld of sounds that make something cool. Dream Pop kind of stuff, basically. Do you think it was because of the mentality, or just because of chance? Or, do I just not know what I'm talking about?