The whole idea behind copyrights is that the creators have the exclusive right to content of their work. That means songwriters own the lyrics and melody while performers own all recordings of the performance. That copyright does not include chord progressions, drum patterns, musical styles, performance styles, or subject matters.
IMO it shouldn't include style either. There are too many great works of art that have been made from fusing other styles and bringing them to the next level. For instance, Michael Jackson's classic "Billie Jean" performance which was based on a Gene Kelly routine and a Soul Train dance. Also art is often too subjective to prove that one person copied another's style. If, for instance, Chuck Berry were to sue the Beatles for ripping off his style, all the Beatles would have to do is find a public domain recording of an artist with a style somewhat similar to Berry's and claim they copied him instead. It's a lot harder to do that with words and music.
The Blurred Lines case was a travesty. The only reason Thicke and Williams probably lost was because of their arrogance. Ed Sheeran ripped off Marvin Gaye's style far worse with his cover of Let's Get it On (AKA "Thinking Out Loud), but the Gaye family didn't sue him. Probably because they knew they weren't going to clean up twice.