Judicious use of compression isn’t a bad thing. George Peckham, whose masterings are sought after (Porky, Pecko, etc.) used a classic Fairchild tube compressor as part of the mastering chain to juice the recordings he was mastering.
To me, music is about building tension, reaching a crescendo and releasing it. That’s true of classical music and of much ’classic rock’: think about the anthemic songs such as "Stairway," or "Freebird" or "Hotel" (yeah, I know, but they got overplayed for a reason and it wasn’t just marketing). Each of those songs has softer acoustic passages that built to a heavier, darker sound; the joy is in the contrast as well as the build up, knowing that things were going to get louder, harder and more pounding. (no sexual entendres here but ’rock and roll’ is itself a euphemism for the act).
I like a lot of ’psych-folk’ because it is a study in contrasts. I don’t think jazz fits into this model, but I haven’t thought that one through. (too many different styles of jazz for me to get my head around as I write this).
Highly recommended for a study in contrast is Roy Harper’s "The Same Old Rock" from the album, Stormcock. It is a virtual textbook of contrasts, of one style of playing morphing into another. It didn’t hurt that Jimmy Page played acoustic guitar on this track.
