Because my own command of logic is hampered by my right-brain bias, and I am frankly stumped by this case, I have summoned from a distant space-time locus perhaps our greatest logician, Mr. Spock, to iron things out. Here is an excerpt from my interrogatory.
AH: This case does seem riddled with contradictions and, forgive me, blurred lines. Can your incisive Vulcan mind cut through the muddle for us?
SPOCK: Indeed, it is a paradoxical case, particularly since it is colored by human sentiment, and by uniquely human concepts like "groove" and "feel" to which I am, in part, alien. But one line is not at all blurred. Thicke and Williams decidedly did not "start with a blank page." In fact, I would argue that they engaged in a process which has only recently become technologically possible in your world, and that it produced something that comes closer to the meaning of "counterfeit" than outright theft of intellectual property. Let us call it, for lack of a better term, "digital grid mapping." The defendants all but conceded their desire to possess whatever it was that leant the Marvin Gaye recording its special qualities. Why? Because "Got To Give It Up" had been a hit record and they desired the same. The technology available allowed them (in the remarkably short time of an hour and a half) to simply "overlay" their as-yet empty template on Mr. Gaye's song grid and lift an "aurostatic impression" of those elements they found hit-worthy in the original, including--yes--the cowbell. They then selectively discarded elements that didn't suit them, and repositioned or gave new emphasis to others (e.g., the "You sexy lady" refrain in the background vocals is moved to the foreground as "You know you want it"). All of this is a perfectly logical, even scientific way to evaluate a commercial product. And as I comprehend it, record industry practice provides avenues for credit-sharing should you decide to use copyright-protected material. But if Budweiser, for instance, were to replicate Andy Warhol's silk-screening technique perfectly, replace the Campbell's Soup can with a beer, and run the advertisement without permission, would it not cause difficulties?
AH: But agreed-upon metrics in these cases are important, don't you agree, Spock? And the metrics we've used so far are things like common note sequences, melodic shapes, chord progressions, lyrical similarity. These two songs don't seem to share any of those things in the way that, say, My Sweet Lord did with He's So Fine.
SPOCK: Metrics, as you call them, are indeed important. But they have value only to the degree they reflect current practice. Some standards, such as the requirement to show that the defendant had "access" to the protected work, will endure. Others will not, or will require updating. Technological humans are now fully entering the age of mimesis that began with the printing press and will end...well, I could make a logical conjecture, but...
AH: Yes, but isn't it a slippery slope? What songwriter will feel safe in paying musical homage or borrowing a lick? We've always agreed that you can't copyright a "feel." Doesn't this set a terrible precedent?
SPOCK: On the contrary, it is a long overdue updating of antiquated law. And any songwriter can feel safe as long as his ears (chuckles as he pulls on a Vulcan ear) don't "prick" with recognition. As long as the writer makes the song his or her own.
AH: That's a pretty subjective metric there, Mr. Spock. Ears pricking?
SPOCK: Well, we are talking about music, not a piece of integrated circuitry. It is, after all, "a feel thing." Vulcans don't listen to a great deal of pop music. But even I can read a map.
In the present era of popular music, it is no longer solely things like "melody" and "chord progression" that define a work. Textural and timbral elements are part of composition. A hit record is, by my Vulcan calculations, about 69% "feel." And that feel is, to use one of your more unfortunate human neologisms, "monetizable." If anyone knew this, Mr. Thicke--in spite of his Vicodin haze--did. A hit song is a 'holistic entity,' not simply the sum of its notes and chords. If I were to perform a digital grid mapping of the first movement of Mr. Beethoven's 9th Symphony, lifting tempi, meter, rhythm, accent, dynamics, and instrumentation into my own grid--without stealing a single specific melodic figure or harmony, I would be guilty of a kind of digital soul theft. No Vulcan court would ever convict me. It would see such a concept as illogical. But in your world, "feel" trumps logic.
Ever more frequently, your finest composers are being asked to produce something that sounds like something else. If the "Blurred Lines" verdict is allowed to stand, it will send a warning to producers who would exploit the greatness of another work for monetary benefit that by asking composers to abet them, they are compelling them to break the law.
AH: Thank you, Spock.
SPOCK: It has been a pleasure. Live long and prosper. Honestly.