First off, congrats to the final 5 for making it this far!! I would love to be back for that finale if I got the chance to
Anyways, I'm just going to say my judgings for each trinity:
holyground - Katy Perry - Overall, a good trinity, and I liked the way you formatted it. My issues came from the fact that you bashed most of Katy's writing skills at the end there, which wasn't necessary in my opinion, and that you chose Choose Your Battles, which is not one of Katy's best songs. If you wanted to go for something more "ballad-y," I would've chosen Not Like the Movies or The One That Got Away, especially because those are both pretty mature songs.
Musickid203 - Ke$ha - Also, a good trinity, especially for someone who doesn't have that much knowledge on Ke$ha. TiK ToK and We R Who We R were both good choices; however, I slightly wish that you chose something else other than We R Who We R since TiK ToK is kind of a similar song based on its sound. Maybe Last Goodbye or The Harold Song would have been better. However, Dancing with the Devil was a really good choice as well, so props to you!
Kyle. - Beyonce - I actually liked this trinity a lot because you didn't pick songs that were that predictable like Single Ladies or Irreplaceable. My only thing is that I'm not the biggest fan of the song Diva, so maybe it should have been ***Flawless instead, but with that, I appreciated the fact that you picked songs from 3 different albums.
Sebas - Madonna - So, I'm actually not a big fan of Madonna at all; in fact, she's one of my least favorite artists, but I'm going to act unbiased. That being said, this was a really good trinity and your reasonings were solid as well. The last song in the trinity, Sky Fits Heaven, was not a good choice, just because it honestly isn't the best song in the world. I would've gone for maybe something like Music or even Hung Up since the latter is kind of a reinvention/reintroduction of old sounds in new music.
TheSeenScene - Kelly Clarkson - I'm a big fan of Kelly's, so I have some knowledge behind her music. I liked this trinity, but I feel like better songs could have been chosen. Behind These Hazel Eyes was absolutely a perfect choice. Mr. Know It All was a decent choice, but I would have picked either Sober, or if you really wanted to stick with the album Stronger, then you could have picked Stronger (What Doesn't Kill You). Finally, Tie It Up is a cute song, but definitely, not one that belongs on a trinity. If you truly wanted to go the country route, I would have chosen Don't You Wanna Stay because that's just a better song in my opinion or just gone a different route on the last song.
I'm really sorry to the people that I'm voting out because you guys are all strong and did pretty well with the theme, BUT my two off votes go to
TheSeenScene and
holyground.
to both of you
EDIT: This explanation is so long
choices, could've done so much more.
Glad to see people who aren't big fans of Madonna liking my entry. 
This is Katy PERRY not Hudson