"We owe it to song writers around the world to make sure this verdict doesn't stand," Howard King told Fox Business News Wednesday.
"My clients know that they wrote the song Blurred Lines from their hearts and souls and no other source."
Marvin Gaye's heirs took Thicke, Williams and rapper T.I. to court, claiming they copied the late Motown artist's 1977 song Got to Give it Up when crafting their 2013 hit Blurred Lines.
The song earned more than $16 million US in profits, with Thicke and Williams making more than $5 million each.
The trial focused on detailed analyses of chords and notes in both Blurred Lines and Got to Give It Up, but jurors never listened the actual recordings of either songs, because Gaye’s family only owned the copyright to the sheet music for Got to Give It Up.
This fact is likely to figure prominently in the artists' appeal.
"This jury didn't listen to any music, which is rather surprising to me," said King. "The fact, is harmonies are different, the chords are different and the notes are different."
"We are going to exercise every post-trial remedy we have to make sure this verdict does not stand," King added.
A number of industry experts have expressed their skepticism of the verdict and expressed concern it could confuse matters of musical copyright infringement and cast a chill songwriting.
Questions are already being raised about the possible similarities of between Williams's smash hit Happy and Gaye's 1965 track Ain't That Peculiar, but King says inspiration and theft are two entirely different things.
"Pharrell has readily admitted that Marvin Gaye is one of his idols, but it's silk and rayon," said King.
"If this is the way the law is going to go, then the creator of rayon better look behind him for lawsuits from the owners of silk, because even though they feel the same, they are structurally completely different — just like these songs."