Pop music for the most part is a redundant art these days. There are only so many chord progressions you can go through before you start repeating something that likely was done many times before by many other artists. The smaller nuances and melody variations are what allow G-Em-C-D to be used literally thousands to times on commercial singles without many accusations of plagiarism.
Yet from time to time, the charge of being a copycat is leveled against an artist, usually on the basis of similarities within the melody more so than chord progressions or rhythmic similarities. And for the most part, it seems that the public reaction to such a claim has more to do with the parties involved than with the actual work at hand. For example, take these three recent cases into consideration.
Coldplay vs Joe Satriani:
Satriani sued in December, but what's interesting here is that most people's opinion on the musical similarities has less to do with the melody at hand, and more to do with their opinion of Coldplay. That is to say, those who love Coldplay think a claim of plagiarism is absurd, but those who hate Coldplay couldn't be happier to have another reason to find their music abhorrent. The fact that a respected musician is going after them adds to the intrigue. Everyone knows Satriani is one of the most amazing guitarists living, and yet nobody actually likes his music. He just seems like someone with credibility to music critics and middle-aged cover bands. Expect a similar reaction should Steve Vai ever sue anyone.
U2 vs Escape Club:
Some have compared the new U2 single to Elvis Costello's "Pump It Up" or Billy Joel's "We Didn't Start the Fire," but these comparisons don't hold water, because both those songs are far better than this. Remember four years ago when "Vertigo" was being shoved down America's collective throat? It was awful, but it was a semi-original kind of awful (or at least as original as U2 gets anymore.) This song is awful, but is also derivative of a song that was universally regarded as terrible when it was first released twenty-five years ago, when Escape Club themselves were accused of ripping off Elvis Costello. There has been no lawsuit filed as of yet, presumably because the members of Escape Club figure that any monetary gains will be outweighed by reminding the public that they are in fact members of Escape Club.
It should be pointed out however that not all plagiarism is worthy of ridicule. In many ways, judgment of stylistic rip-offs is dependent on whose style is being ripped off in the first place. It's not just the case when it comes to music. Critics of Paul Thomas Anderson would point out that his ambitious tracking shots are derivative of Martin Scorsese, but that doesn't make them less impressive. There are fewer ways to re-invent the wheel, so if you have to imitate, you might as well imitate the best, right?
This was on my mind as I recently heard the title track from the new Kelly Clarkson album:
That bass riff sounds downright Spoon-tastic, does it not?! And yet ultimately, it's a killer pop song. When I heard this, I didn't think "She's totally ripping off Spoon." What I thought was "I wish more bands and singers had more songs that sounded like Spoon." FM radio/MTV/ABC dramas would be enhanced if their soundtracks consisted of better music, so if that happens as a direct result of co-opting aspects of better bands, then we come out ahead, don't we? Ultimately, perhaps that's the key with pop music. Everything is going to be lifted in some way from something that came before it. But who it's being lifted from makes a difference.