I tend not to be sentimental about the loss of great packaging for music. Stripping music of its container is of course impossible, but it remains in my mind the ideal worth trying to approach, so that in listening to songs I am not merely vicariously experiencing the thrill of getting to pretend to be the rock star who made it or believe I've joined some subversive cult of insiders or that I'm living some glamorous luxe life. But in some ways, pop music is the province of consuming cultural images and claiming ownership of certain aspects of the zeitgeist. This is why it is often inseparable from the hype that otherwise seems to encrust and suffocate it. If I were serious about approach my ideal, I'd probably invest more time in classical music, which comes with far fewer signaling aspects -- aside from the great big one that you consider yourself to good for common contemporary culture. It would inevitably betoken an unwillingness to participate in the now.
Anyway, the only place I see album covers in the flesh these days is in thrift stores, and I never know what the album covers of new records look like. I couldn't possibly tell you what a My Morning Jacket album cover looks like, even though I am pretty sure iTunes has downloaded little jpegs for them automatically. This hasn't affected my appreciation of the albums at all, and may in fact have enhanced it. If I knew how they were trying to represent themselves, I'd probably be annoyed; as it is I can pretend they are Neil Young and Crazy Horse.
But when I look at posts at the excellent LP Cover Lover blog, I realize that some album covers were far more important than the music contained on the vinyl within them, and that that music is basically unthinkable and certainly would have been unsellable without the context-establishing images the covers provided. Consider this cover, for A Moment of Desire by Jay Clever and his Orchestra. It's on the sleazy end of the spectrum, to be sure, but it's emblematic of scores of easy listening albums from the 1950s and 1960s, when adults made up the bulk of the record-buying public. The cover gives no indication of what the music will sound like, but that makes it even more likely that it will determine what we hear when we listen. Obviously the goal of the cover is to persuade consumers that this record will make a sexy soundscape in the immediate proximity of their hi-fi set. I'm skeptical whether music can be inherently "sexy," but the ambiguity of that question makes covers like this one effective; it opens the space for images to be created in one medium and translated into an entirely different experience. This is also how ads are meant to work; through contiguity and juxtaposition, products are associated with more or less unrelated emotional states. They tend to work because we want to believe its true, that instrumentally conjuring a feeling is just that easy.