Robin Thicke and Pharrell have been in court, fighting the estate of Marvin Gaye over allegations they swiped the sound of "Blurred Lines," the earworm of the summer of 2013, from the 1977 Gaye hit "Got to Give it Up."

It's been an interesting legal process to say this least. For one, Thicke tried to get out of any responsibility for the theft by arguing he had little do to with the song writing process because he was high on Vicodin and alcohol in the studio, and only started pushing for credit when the song became a hit. (A weasley strategy yes. But given Thicke's wobbly public persona and his otherwise mediocre catalog, also likely accurate.)

Now, in court documents revealed to TMZ, both Pharrell and Thicke are claiming they borrowed from Gaye because, like, Beethavon.

In the docs, they admit 'Blurred' starts with repeated notes, just like Marvin's song does -- but also like Beethoven does in his famous 5th Symphony. All together now ... da-da-da-dum! Their point -- musicians have been using repeating tones since the dawn of time ... or at least since 200 years ago when Beethoven was doing his thing.