I have been thinking that my next blog post would somehow be about pop music, since my next venture in this world is a bona fide rock band that's planning to play the odd scraps of pop music I've churned out over the past half-decade or so. So I'm grateful that Nobel laureate and everyone's favorite (or most-loathed) economist Paul Krugman put his foot in the pop-classical chasm. And put his foot in it he did, from the perspective of your local cyberhood art music composer. First moment of trouble:
I guess the first thing to say is that while I grew up in a house saturated with classical music, in my late middle age I find great solace in the fact that people are making great music now.
This prompted an obvious, if necessary retort from that overseer of all musics contemporary, Alex Ross: 
Among notable rejoinders in the Comments section (generally a reliable melting pot of whackjobs of all stripes) of Krugman's blog post is a three-paragraph response from notable composer Derek Bermel. He takes particular issue with the following statement by Krugman:
it’s clear, if you think about it, that the real classical music of my generation — classical in the true sense, meaning that it endures and will continue to be played for a long time — was actually pop/rock/folk. It may offend some peoples’ sense of dignity, but the reality is that the Beatles are at this point as solidly embedded in the Western canon as Beethoven and Brahms — and rightly so.
Bermel responds:
...There are so many things wrong with this statement. How is it clear, and what is the evidence that Feist and Arcade Fire will endure? Because the Beatles did?
Music, and art in general, is a fluid thing. In cultures around the world - not only Europe but also China, India, Indonesia, also in Africa and South America - 'classical' performance traditions are preserved and passed along with care to successive generations. This requires time, energy, and money, but it is worth it. The strange thing is that celebrated pop musicians - including Elvis Costello, Lady Gaga, Paul McCartney, Stevie Wonder, Trent Reznor, Johnny Greenwood, Alicia Keys, Billy Joel, Bryce and Aaron Dessner -- and on and on -- acknowledge the value of classical music; they appreciate, support, and even write for the concert hall.
I agree with Bermel that there's much wrong with Krugman's statement - though I'm not 100% sure what his (Bermel's) subsquent point is. Perhaps it is a distinction between 'classical' performance traditions, which need to preserved and passed along at great expense, and popular onces, which are enmeshed - and in some sense compromised by - the mass culture industry. This argument is deeply interesting, and has interested scholars back to the granddaddy of anti-pop philophes, Theodore Adorno.
From my perspective Krugman's crime is oversimplification. The difference between "classical music" and pop, or say "art song" and "pop song" is very, very complicated. Certainly proximity to the arms of mass dissemination does matter in evaluating a work's stature as art or product. It's simplistic to say the classical music of our time was pop, rock and folk - even aside from the absurd diss that implies to the Pendereckis, Glasses, Reichs, dare I say even Stravinskys (who was active in the love decade), and more recently the Towers, Wolfes, Curriers, Adamses, etc. who have, in fact, been busy writing...the classical music of our time. The pop music we still talk about after decades is important because, at least in part, it sold lots and lots of records, and made lots and lots of money. That is true of just about every pop record whose admittance to the canon is under consideration.
It is not really my interest to pursue that much further - since it's been done elsewhere. Are the Beatles the new Beethoven? That is a tough question. Beethoven - and almost ALL of his classical brethren (forgive the masculine term, but if we're talking pre-20th century it is what it is) are most esteemed for their large form compositions. Beethoven's symphonies, sonatas and quartets are the epicenter to his claim as an eternal. For Mozart - it is his operas. Lots and lots of other great stuff, but without the operas, I don't know that people would be developing Mozart Oversaturation Syndrome with the same frequency that they are. Go down the line, and find me a composer who is esteemed for his or her songs? Schubert? True. Though some were gathered in cycles - which were the rock albums of their day and you're kidding yourself if you think otherwise. But Schubert does have a bunch of large form works that are celebrated - the few immortal symphonies (the one and a half, let's say), and his share of quartets, quintets, and sonatas. But he is the exception that proves the rule, insomuch as it's his songwriting that grants him immortality. Says me.
There's Hugo Wolf. But I think I've said enough about him.
Are the Beatles great art? I can't imagine arguing otherwise - and the number of thinking people who can is dwindling. Even back in the day, as staunch a conservative (at least in these matters) as Ned Rorem was proclaiming their ascendance into the pantheon. But what they didn't leave us with - what so few pop artists do - is a catalogue of long forms. Yes, there's Abbey Road side 2 - which is absolutely a multi-movement symphony. And then the whole of Sgt. Pepper's, and the coherent (but not necessarily un-reorderable) Revolver and Rubber Soul.
I do not say this to denigrate their accomplishment. I'm more saying that that is what pop music is. It's the short form in all of its glory. It's the thrill of a good idea - because few if any great pop songs are written without a great idea. You have to have one, because there's no time for significant development. Beethoven was famously a mezzo mezzo melodist. I mean, it took him what, three decades to write his only truly great pop tune? The fifth symphony "tune" in anyone else's hands would have been simply an uninspired melodic fragment, leading nowhere in particular. You can get away with that if you're a) writing a long form where the brilliance of your individual ideas is rather secondary to what you will do with them and b) Beethoven.
A pop song needs a good idea. Often that good idea is "the hook" - and most good pop songs have one (and many good "art songs" don't). In a quite interesting book that as far as I can tell no one's read or heard of, Walter Rimler argues the best rock songwriters generally accomplish their greatest work under the age of 25. I think there is some truth to this. That is the time when good ideas are flooding the mind of a talented writer (I've met some). The ideas come fast and furiously, and must be processed and made into work. A great pop song should take at most an afternoon to write (though finishing the words can take a year). The Kinks' early hits - if you believe Ray Davies - generally took under half an hour (you'll note "You Really Got Me" has precious few words to slow things down).
This too is not meant to denigrate pop, which I love, and to which I am returning. It's more to say that great pop, a great pop song, most often has at its center a great idea. And that idea is then fleshed out - and given supporting matter (often, verses) so that it can shine. You write your best pop songs when you're young, impatient, don't know any better, don't question yourself, and learn to recognize a good idea when it invades your headspace.
I write both "classical" (which is such a loathsome term) and pop music. I have no trouble, at this stage of my artistic development, beginning a classical piece. I put very little emphasis on how such a piece begins. Any beginning can lead to a great piece - it doesn't matter so much. How I develop my material, how I let one thing play against another, expand one melody, contract another, combine them, change rhythm, and on and on - these are the things that will matter. Sure it's nice to have a piece start like Beethoven's Fifth - which the great master fooled you, after the fact, into believing was not only a great, but perhaps the great idea. But it is not necessity. Workaday materials - in an extended form - can yield a whole that far transcends the sum of its paltry parts.
Not so with pop songs, and I don't try to write them anymore. I wait for them to find me. They start with an idea, which is usually offered immediately by yours truly to iPhone Voice Memo (because I've learned that I remember nothing). They come in bunches, and then they don't come at all - no ideas, for months at a time. I can still write classical then - because I don't really need ideas to do that. And I'm fortunate, or unfortunate, not to have to earn my peanuts writing hits.
Whether Arcade Fire is writing "Art Songs," as Krugman contends, is a discussion for another day - and one that I think is worth having. There may be a continuum between the song that is pure art, and the one that is pure product. But I like the tensions that spill forth when we force ourselves to draw a line and take a stand. I also like forcing people to name the five best Beatle songs, which is insanity.
Krugman, by simplistically saying that pop, rock and folk are the "classical" music of his generation, not only deals a profound gut punch to a class of highly effective artists who don't deserve it, but also misses some important distinctions between the two genres. Again - I don't believe in a hard fast division, I believe in a continuum. But I believe it's really there, and while I love the two genres equally (perhaps I love one more equally than the other, but I'm not telling), I'm not ready to toss aside the difference.