I have experience in copyright litigation, but not as it relates to music. This appears to be the gist of the law in the 1st Circuit, which is probably similar to the 9th Circuit where the case is pending in district court (I believe):
As much as the law might be based on an "ordinary listener" test, the reason I think this case will settle is because the judge or jury will be guided by experts on both sides. Also, that GQ interview is not an admission of guilt but it will definitely help the Gayes.
To succeed on a claim for copyright infringement, a plaintiff must prove ???(1) ownership of a valid copyright, and (2) copying of constituent elements of the work that are original.??? Feist Publ'ns, Inc. v. Rural Tel. Serv. Co., Inc., 499 U.S. 340, 361, 111 S.Ct. 1282, 113 L.Ed.2d 358 (1991). As part of the second prong, a plaintiff must prove that the copyrighted and alleged infringing works are ???substantially similar.??? Johnson v. Gordon, 409 F.3d 12, 18 (1st Cir.2005) (citation and internal quotation marks omitted).
In determining substantial similarity, courts apply the ???ordinary observer,??? or, ???in musical milieu, the ordinary listener test.??? Id. (internal quotation marks omitted). A defendant's work is substantially similar to the copyrighted work only if an ordinary person of reasonable attentiveness would, upon listening to both, conclude that the defendant unlawfully appropriated the plaintiff's protectable expression.
As much as the law might be based on an "ordinary listener" test, the reason I think this case will settle is because the judge or jury will be guided by experts on both sides. Also, that GQ interview is not an admission of guilt but it will definitely help the Gayes.