UPDATE: IF THE NOTES ARE NOT THE SAME, WHO IS TO BLAME?

Following a series of headline-grabbing depositions, Pharrell Williams and Robin Thicke filed a reply in support of their motion for summary judgment Sept. 22 in the contentious infringement case involving their hit "Blurred Lines," the biggest song of the summer in 2013, and the late Marvin Gaye's "Got to Give It Up."

The filing mainly addresses the testimony of musicologist Judith Finell, maintained by Gaye's side as an expert witness, who concluded that the two songs had a "constellation of similarities." Williams and Thicke point out that the notes themselves in the allegedly similar portions of the songs are almost totally different, and argue that these extrinsic differences doom the infringement claim.

"The notes do not lie," Williams and Thicke said in the filing. "They are not the same here."

Got to Prove Substantial Similarity or Give It Up.

Copyright infringement can be difficult to prove, requiring demonstrations of access to the copyrighted work and both extrinsic (concrete elements based on objective criteria) and intrinsic similarity (whether the ordinary, reasonable person would find the total concept and feel of the works to be substantially similar) under the Ninth Circuit standard

Williams and Thicke base their arguments on a musical transcription of the "Got to Give It Up" recording. For example, here they provide a comparison of the two songs' "signature phrases" ("good girl" in "Blurred Lines," "keep on dancin'" in "Got to Give It Up"), with every note that differs in pitch and placement whited out:

blurredlines_signature

Williams and Thicke argue there's no infringement because the notes of the two songs are extrinsically different, with no similarity in "rhythm, harmony, and melody" (as supported by the testimony of their own musicologist). They also say that, at worst, they may have borrowed non-copyrightable ideas from "Got to Give It Up"; both Williams and Thicke admit in the motion that they are "huge Marvin Gaye fans," fulfilling the requirement of access to prove copyright infringement.

'Unusual Cowbell Instrumentation.'

Gaye's estate has taken a more holistic approach, arguing that the sum of "Blurred Lines'" parts infringe even if the notes used aren't exactly the same. Gaye's estate says that the relevant parts still have objectively similar pitches, intervals (the melodic distance between different notes - for example, a B to a C and a C to a D have the same interval of one step), and rhythms.

The estate also cites similar artistic choices in each song that differ from most other songs, like "party noises, unusual cowbell instrumentation, omission of guitar, and use of male falsetto" that, combined with other musical elements, proves substantial similarity. These artistic choices are also what Williams and Thicke appear to refer to when discussing non-copyrightable ideas.

The opposing arguments are notable for their different interpretations of extrinsic similarity–if the notes aren't the same, how objectively similar can the songs be?–and intrinsic similarity vs. unprotectable ideas. It should be interesting to follow the case as it continues to unfold.