I wouldn't normally say this, but... I'm about to spill the true tea, y'all.
Keep in mind that I'm a stan for both Ke$ha and Lady Gaga, so I'm being very generous with my comments to both. Neither of them are rockstars, they are popstars. But the OP is not asking who is more of a rockstar, they're asking "who's more natural at rock", in which the answer is Ke$ha. I'm not saying that Gaga can't pull off a rock song, but she's clearly more naturally pop.
Ke$ha grew up on rock music, she loves rock music, and that's where her heart is. She loves making pop music as well, but it's not her natural genre. Being a rockstar or making rock music does not define whether you are more natural at rock. In 2010, rock was not a mainstream successful genre. Still today, it is not. Going down the dance-pop route was the best thing that Ke$ha could have done... it's what gave her a #1 hit in TiK ToK and a #1 album in Animal.
Back to the subject at hand, I'm absolutely convinced that most people who are making comments along the lines of "Lady Gaga, it's not even close" or "There's absolutely nothing rock about Ke$ha", are seriously misinformed, and I'm sure haven't even listened to her album tracks that weren't singles, let alone her unreleased collection. The OP obviously listed her for a reason... Ke$ha loves rock music, has written/recorded rock songs, worked with rock legends and has the attitude of a rockstar.
And it's not just me who thinks this. I have receipts.
http://www.theatlantic.com/entertain...k-star/265811/
So all of you misinformed Monsters can either educate yourselves and continue to say that Gaga is naturally
better at rock, while acknowledging that Ke$ha is still pretty darn good at, or take a seat and keep on replaying Sex Dreams while you wait for ARTPOP to leak so that you can download it and pretend to actually support her career.