One of my vacation reads for a recent trip out of the Tucson summer was Susan Jacoby's The Age of American Unreason, an examination of anti-intellectualism in recent American history, the dumbing down of our culture. One of her examples is the elevation of pop music to the same level as classical, "as if this particular pop manifestation possesses a mystical and philosophical significance raising it above the level of mere entertainment." Serendipitously, Greg Sandow has had a recent series of posts with the thesis that pop reviews "will be more compelling for general readers, because the music will be connected to the world outside, and the review will show that." Both authors seem to be talking about the same topic, and whereas Jacoby oversimplifies the subject, Sandow takes a more nuanced approach (helped in part by the extensive comments).
Part of the question revolves around the degree to which pop music can be "serious", and to some extent what it means for music, pop or classical, to be "serious." Jacoby takes Beethoven's Ninth Symphony as the standard, but this is a difficult standard for any other piece to attain. She would have a more level playing field with something like his Seven Variations on God Save the King, or even Für Elise. The Ninth Symphony is a massive and complex work, and anyone would be hard pressed to find similar constructions in the pop world, in length as well as the forces required to perform the piece.
But it's difficult to find criteria for what might make pop music "serious," even though individual listeners can offer examples. Is Radiohead serious? Bjork? Is "popularity" any kind of measure? Must all music be divisible into "pop" and "classical"? For many years, I organized my record collection that way, and inevitably there were some questions. My first Laurie Anderson album, United States, was filed under Classical because I first heard her on our local classical station (the New Music America broadcasts in 1982) and because the record was recorded live at a classical music school (the Brooklyn Academy of Music), but her later work showed her more as a pop artist. I had the complete run of Obscure Records; where to file them (they ended up under Pop)?
Since the advent of ubiquitous recorded music, with the ability of an artist to find an audience independent of live events, the boundaries of "pop" and "classical" music have become more fluid, more fictional. I organized my CD collection into pop and classical as well until my wife complained that she could never find anything, and couldn't we please have a finer grain classification. So I split everything up, and we got pop, classical, jazz, world, ambient, electroacoustic (even in the pop/classical split, I never knew what to do with the likes of Bernard Parmegiani, so it always had its own area — my wife never went browsing there anyway), and the largest area was everything else. The equivalent of the Unclassifiable genre in iTunes. My wife liked the new layout, and one day she put some labels on the various shelves. The everything-else section got the label "nails on blackboard". Tongue in cheek perhaps (but perhaps not — I do have a little bit of Merzbow), but I believe it reflects a desire by many creative artists to expand beyond the boundaries of any established genres. Where else would you file John Wall, Hafler Trio, Ryoji Ikeda, Boris, Keith Rowe, and the countless other artists who have followed their own muse? Here are artists that have a most serious intent, but their releases are often limited, certainly not "popular" in any accepted meaning of the word, and don't follow the "classical" paradigm where the composition exists as a separate entity from its recording or performance.
Sandow's and Jacoby's discussions inadvertently miss this mysterious aspect of music, intellectually challenging and virtually invisible to the corporate world. Sandow has recently pointed out that complexity is attractive, that there is an audience for new music whose complexity reflects and comments on the uncertain world in which we live, and being outside of the mainstream is part of the attraction. But both writers focus exclusively on classical music as the top of the hierarchy, instead of simply a node in a rhizome.