Most copyright lawsuits in the songcraft realm begin with a comparison of two works. A new legal action targeting "Happier," an international smash from Marshmello and Bastille, adds a wrinkle in the form of a third song as the plaintiff must also implicitly show what his work is not.

The plaintiff in the case is Arty, a successful DJ/producer who authored "I Lived (Arty Remix)," which is itself an authorized derivative of "I Lived" from the band One Republic. Arty (Artem Stoliarov) alleges that "Happier" is an infringement of "I Lived (Arty Remix)."

Just because Arty's song traces to another doesn't mean he can't sue for copyright. Instead, he enjoys ownership over any original elements added to One Republic's version. A complaint filed Monday in California federal court acknowledges that Arty doesn't claim dominion over the underlying "I Lived" composition from New Republic but nevertheless attacks the songwriters behind "Happier" for "willfully copying" the "original composition elements" of his own remix "note for note."

The defendants in the lawsuit include Marshmello (Christopher Comstock), Daniel Campbell Smith, Steve Mac and various music publishing companies.

Arty is represented by attorney Richard Busch, the attorney perhaps most famous for representing the Marvin Gaye family in the "Blurred Lines" suit.

Here's the full complaint, which goes into more musicological detail about the alleged similarities and, in particular, a synthesizer melody that's described as nearly identical in pitch, metric placement and rhythmic duration.

And here's all three songs for anyone ambitious enough to play detective...