Dave Eggers has a theory that we play songs over and over, those of us who do, because we have to "solve" them, and it's true that in our early relationship with, and courtship of, a new song, there is a stage which is akin to a sort of emotional puzzlement.
There is a bit in "I'm Like a Bird," for example, about halfway through, where the voice is double-tracked on a phrase, and the effect---especially on someone who is not a musician, someone who loves and appreciates music but is baffled and seduced by even the simplest musical tricks---is rich and fresh and addictive.
Sure, it will seem thin and stale soon enough. Before very long I will have "solved" "I'm Like a Bird," and I won't want to hear it very much anymore---a three minute pop song can only withhold its mysteries for so long, after all. So, yes, it's disposable, as if that makes any difference to anyone's perceptions of the value of pop music. But then, shouldn't we be sick of the Moonlight Sonata by now? Or Christina's World? Or The Importance of Being Earnest? They're empty! Nothing left! We sucked 'em dry!
That's what gets me: The very people who are snotty about the disposability of pop will go over and over again to see Lady Bracknell say "A handbag?" in a funny voice. They don't think that joke's exhausted itself? Maybe disposability is a sign of pop music's maturity, a recognition of its own limitations, rather than the converse...
A couple of times a year I make myself a tape to play in the car, a tape full of all the new songs I've loved over the previous few months, and every time I finish one I can't believe there'll be another. Yet there always is, and I can't wait for the next one; you need only a few hundred more things like that, and you've got a life worth living.