So far Perry's been winning handily. In the 12 weeks that both singles have been out, "Roar" has lingered around number one and "Applause" around number ten, at times outperformed by Ylvis's novelty song "The Fox." But the promotional push for Gaga's Artpop album—as high-theatrical as we've come to expect from her—is only now starting to kick in, and things may change yet.
Perry's big advantage over Gaga is her eagerness to please, which manifests itself in far bigger, more easily accessible hooks than Gaga's normally willing to put out there. Gaga's advantage is that she's interesting. For the lead single from a major pop star (not to mention a song about audience-pleasing) it's almost defiantly awkward, with Gaga affecting an oddly stagey voice and singing such ungainly mouthfuls of lyrics as, "I've overheard your theory, 'nostalgia's for geeks' / I guess sir, if you say so, some of us just like to read." Her songs give listeners a lot more to chew on afterward, something that the denizens of the Top 40 who aren't repping hard for reading don't really offer.
This might be what gives Artpop a crucial edge over Perry's Prism, the fact that it isn't so eager to be understood. Hearing "Roar" will flip the pop-satisfaction switches in your brain, but "Applause" also gives you little puzzles, like what the fuck the line about "One second I'm a Koons, then suddenly the Koons is me" even means. (It turns out to be an allusion to Artpop's cover art, which features a Gaga sculpture by Jeff Koons.)
Currently the second and third singles from Prism and Artpop are charting as well, with Perry's leading by just a little bit. But while Perry's are more immediately pleasing, Gaga's playing a long game that has a good chance of coming out ahead. She'll certainly be the more fascinating part of this competition to watch.