I find many of these correlations may fit a lot of commercial, popular music which I generally don't listen to. Recordings with fine sound quality have always existed through time and genre, just more likely with music not made for mass consumption. I agree this became more difficult with innovations in portable audio, vast majority of my 50's-60's recordings all wonderful sound quality, starting in 70's these issues became more apparent.
Implications of vinyl on musical trends?
I’ve been super enamored with vinyl since making the leap from digital. My mom gave me her old records; mother-in-law gave us hers; aunts and uncles have offered theirs, etc. Throughout my life it seems vinyl was always around. Maybe it was tucked away in a closet, but it was there—albeit a bit dustier during the 1990s. As a result of its ubiquitous nature, it logically influenced musical trends in a similar hand-me-down sort of way (e.g. blues to Zeppelin et al).
I’ve watched over the years as rock & roll struggled and was always a bit vexed by it. I generally chalked it up to aging; but, it struck me that maybe the decline of vinyl directly contributed to the decline of rock & roll. Could it be that the decline of vinyl caused some sort of musical schism? Or, maybe the “decline” was simply another evolution (though to what, I cannot say)? I find it interesting that the resurgence of vinyl seems to correlate with a younger rock movement (e.g. Greta Van Fleet). Nothing deep, profound, or particularly meaningful…just something I was thinking about on a random Saturday.