An eclectic group of artists from R. Kelly to Hans Zimmer tell the 9th Circuit that the verdict, if allowed to stand, "is very dangerous to the music community."

When Pharrell Williams and Robin Thicke first launched a lawsuit three years ago to protect "Blurred Lines" from claims of having ripped off Marvin Gaye's "Got to Give It Up," there was a sentiment expressed in the court papers that evoking an earlier era and making a work that's reminiscent of a sound shouldn't be judged to be a copyright infringement. Throughout the litigation, from explosive depositions to a jury's huge verdict, that concern has lingered for some artists, composers and producers who have watched the proceedings from afar. Now, they are getting their own chance to speak up in court.

On Tuesday, 212 of them filed an amicus brief with the 9th Circuit Court of Appeals in support of the bid by Williams, Thicke and rapper T.I (aka Clifford Harris Jr.) to overturn the $5.3 million final judgment. The legal brief has enough big names attached to throw one hell of a concert. Among those who are acting as "friends" to the appellants are members of Train, Linkin Park, Earth, Wind & Fire, The Black Crowes, Fall Out Boy, Tool and Tears for Fears as well as Rivers Cuomo of Weezer, John Oates of Hall & Oates, R. Kelly, Hans Zimmer, Jennifer Hudson, Jean Baptiste, Evan Bogart and Brian Burton (Danger Mouse).

These song artists are following the footsteps of Williams' attorneys, who on Aug. 24 laid out a fairly technical justification for why the "Blurred Lines" creators deserve victory in the dispute. The latest amicus brief, though, isn't as interested as discussing the nuances of what evidence the judge allowed to be considered; instead, the document perhaps best reflects how some artists are currently feeling anxious about the restrictions on their creativity. They're warning the 9th Circuit about a potential chilling effect.

"The verdict in this case threatens to punish songwriters for creating new music that is inspired by prior works," states the artists' brief authored by Ed McPherson. "All music shares inspiration from prior musical works, especially within a particular musical genre. By eliminating any meaningful standard for drawing the line between permissible inspiration and unlawful copying, the judgment is certain to stifle creativity and impede the creative process. The law should provide clearer rules so that songwriters can know when the line is crossed, or at least where the line is."

The amici say this case is "unique" because the two works at issue "do not have similar melodies; the two songs do not even share a single melodic phrase."

Instead, they suspect that the jury perceived similarity in the overall "feel" or "groove," which harks backs to the very first filing in the lawsuit. They point out that Gaye himself was heavily influenced by Frank Sinatra, Smokey Robinson, Nat "King" Cole, James Brown and others. They tell the 9th Circuit that there's a "bright line" in film, television and book copyright cases, but that the realm of music hasn't produced any legal clarity about what are "ideas" free to be used by anyone and what's "expression" that's off-limits to be misappropriated.

Hence, their shock at the verdict.

"Such a result, if allowed to stand, is very dangerous to the music community, is certain to stifle future creativity, and ultimately does a disservice to past songwriters as well," they add. "One can only imagine what our music would have sounded like if David Bowie would have been afraid to draw from Shirley Bassie, or if the Beatles would have been afraid to draw from Chuck Berry, or if Elton John would have been afraid to draw from the Beatles, or if Elvis Presley would have been afraid to draw from his many influences."

Read the full amicus brief from these artists below.

Separately, 10 musicologists have filed their own amicus brief, echoing the sentiment that the verdict could curtail creativity in popular music, but with arguments more closely tied to the big subject that will be examined by the 9th Circuit. Specifically, how the trial court allegedly failed in its "gatekeeping function" by not rejecting the case at the summary judgment phase.

Gaye's "Got to Give It Up," released in 1977, was one of the last songs authored before legislative changes went into effect that made sound recordings protectable under federal copyright law. As a result, only the sheet music deposited by Gaye with the U.S. Copyright Office could form the basis of a copyright infringement lawsuit. However, that became a tricky subject when a judge had to decide whether there were any triable issues of substantial similarity and later what evidence could be presented to test a conclusion. Although the judge wouldn't let the jury hear the original Gaye recording, he did permit a stripped-down version to be played. At trial, musicologists testified on behalf of the Gaye family, and Williams' camp believes these experts wrongfully incorporated elements from the sound recordings into their opinions.

In their amicus brief, the music theorists assert "there can be no genuine disagreement among experts as to the fact that there is no harmonic similarity between BLURRED and GIVE because the chord progressions in both works were entirely different," and in a brief authored by Kenneth Freundlich, these amici attempt to zero in on what was actually expressed in the sheet music.

They assert that the judge allowed himself to be influenced by improper evidence and fault the musicologists hired by the Gayes — Judith Finell and Professor Ingrid Monson — for "relying on embellished transcriptions and aligning notes out of the sequence," plus allegedly doing things like offering testimony regarding "implied melodic similarities."

We expect there will be other amicus briefs in this closely watched case. Here's the one by the artists supporting the "Blurred Lines" creators.