Sometimes I hear statements to the effect that musical ideas are only worthwhile if they're unique. As a rule I take the suckerbait and point out that unique does not equal significant. An idea can be unique but insignificant (trousers with a computer keyboard sewn in) or significant but not particularly unique (basic human civil rights.) But somehow the notion got itself screwed into our Western consciousness that you aren't any good unless you're on the bleeding edge, unless your stuff has never been heard or seen or read or felt or tasted. That to be an artist means to be an innovator. That you must "think different", to borrow Apple's ungrammatical but memorable catchphrase.
Except that it ain't necessarily so. Would anybody deny Mozart a place at the table of humanity's great artists? Yet, Mozart didn't "think different." He thought better. A late Mozart symphony isn't remarkable for its revolutionary treatment of form, or for its radically new harmonies, or for its never-before-imagined melodies. There's nothing in a late Mozart symphony that you won't find in the symphonies of any number of other composers of the 1780s. True to his deep mastery of the late Classical style, Mozart handled structure with breathtaking virtuosity but his forms were those of his colleagues—sonata-allegro, aria, minuet & trio, various rondos, variations, etc. He had his own quirks, habits, and preferences, such as his propensity for the older-school practice of avoiding a modulatory transition during the Exposition of a sonata-form movement; instead, he would reach a tonic-key half cadence at the conclusion of his primary thematic group then forge on directly in the key of the dominant, without an intervening modulatory passage. That so-called bifocal close was a common practice amongst the first several generations of Classical composers, although by the 1780s it was dying out. Mozart obviously liked it, using it even in a relatively late work such as the Overture to The Marriage of Figaro, not to mention the late C Major piano sonata K. 545. Formally, the Figaro overture is more reactionary than radical.
You may skip the following paragraph if inconsequential tempests in itty-bitty music-theory teapots leave you unmoved:
Should you recoil from the grayish academicism of the term bifocal close, consider referring to the procedure as second-level default medial caesura. That's the term in the exhaustive (and exhausting) text Elements of Sonata Theory by Hepokoski and Darcy. I submit bifocal close as the lesser of two evils. It's just a crying shame that the old-time Germanic theorists never saw fit to include it in their sonata-form studies; had they done so, we would likely have a properly Anglo-Saxon term. Instead, we're stuck with the polysyllabic Latinate coinages that positively reek of collegiate penis envy.
Enough with the theory lecture. My point is that in terms of Classical forms Mozart was no Livingstone carving his way through the uncharted bush. He used forms as he found them, with breathtaking mastery to be sure and elevating them to dizzying heights of sophistication. His treatment of classical sonata form as witnessed in the C Major String Quintet K. 515 is downright flabbergasting. But it's still classical sonata form. Nothing unique about that.
From the sublime to the ridiculous: television shows. I am revealing no secrets when I point out that the vast majority of mainstream network television shows are written to template, and that they all follow pretty much the same template. One episode of, say, NCIS: Los Angeles is more or less interchangeable with an episode of Hawaii Five-O or CSI: New York or any one of the 11,567,243.2 episodes of Law & Order and its litter of spinoffs. You know the drill: slightly mysterious, psychologically complex but testosterone-soaked head guy played by Mark Harmon or Gary Sinise or Ted Danson or William Paterson. Wiser middle-aged woman with great skills both technical and people. Comic-relief geeks both male and female, socially inept despite being major-league lookers, not a one over 35. The tribal elder who serves equal part deus ex machina and Terminator. Well-groomed but otherwise repellent young women whose razor-sharp tongues complement hair-trigger tempers and frequent outbursts of violence. Dishy 20-something guys stuck in perpetual adolescence who meekly tolerate the abuse spewed forth 24/7 by those buff and surly harridans, displaying all the cojones of a tangerine. Upper-echelon federal agencies (think FBI, NSA, CIA) that, despite being near-perfect copies of Hitler's Gestapo and SS, inevitably come across as the Keystone Kops by the end of the episode.
Yet none of that makes the shows bad in some absolute sense of the word. Unimaginative, oh yes. Uncreative, ditto. But they make a lot of people a lot of money, because a lot of people watch the shows and even apparently find them involving and/or engaging. Don't those gazillions of couch potatoes realize that they're watching the same episode of the same show over and over? Probably. But I doubt they care much about that, because it's the very familiarity of the thing, its rock-solid predictability, that accounts for the attraction in the first place.
It's beyond question that Mozart and Haydn were the supreme masters of their age. But they were joined by hundreds of kleinmeisters, composers who, had they lived in any other era, may well have been considered front-ranking artists by posterity. They flourished in the rich artistic garden of the Classical Era with its lavish patronage of the arts and the upward mobility that awaited the musically gifted. You didn't succeed in the Viennese Classical by offending your patrons or exhausting their ears with unremitting innovation. If you had something new to say, you found a way to do it within the established morés of the time. That remained as true for Beethoven as it did for Mozart or Haydn or Handel or even Wagenseil back in Maria Theresa's day. (Ergo, the occasional openly gay regular character on a cookie-cutter TV crime show. Change happens, but slowly and steadily.) The daringly unique high-wire act that flew in the face of public expectation would have to wait for a different era—and for composers whose livelihoods were less directly dependant on public or patronly approval. Thus Berlioz, Schumann, Liszt, Wagner—extraordinary radicals all, but none depending on their compositions to make a buck. And thus the soggy parade of 20th century composers, most of whom would have swiftly starved to death had they been obliged to support themselves from the vanishingly meager proceeds of their works.