@bentossell Hi Ben! Thanks for your question! Also, thanks to @alincatalin for hunting us on PH!
Firstly, to answer your question as to WHO decides the Best part of a song, "It is any user" . Allow me to explain further :)
1. Mostly all of us have our favorite part(s) of a song, generally the one that we keep playing in loop a.k.a the "Hook" of the song. We just gave a name to the hook --> trbble
2. Any user can submit his/her trbble(s) for any song and just like imgur/reddit others get to vote on them. Based on these votes, we decide the popularity of each trbble and filter them based on genre.
3. If you like a trbble, you can RIGHT THEN & THERE, listen to the entire song on our website :) It's as simple as a click. Also, you can add them to your playlists, favorite them and share with others.
Right now, we are relying on SoundCloud for our catalogue. I might just keep ranting off, so I will wait till there are further questions :)
trbble for Android