Fantastic work, I hardly use apple music (more of a spotify person) but I found myself nodding my head as I read through your reasoning. One reasoning I am not too sure about is the choice to use double tap to like a music choice. I get that you got it from instagram and instagrammers will have no problems transitioning over but you seem to have taken the ability to downvote or “dislike” a song. That negative functionality is important as it allows Apple (and any streaming service) to understand your preferences and play music accordingly. One change you could make to denote a dismissal or as apple puts it “dislike” is use a flick visualization to flick away music you are not interested in. That said, be mindful of the fact that if you are designing for a screen size, the direction of the flick should be the one which users are comfortable with and hence you need to be aware of how users use their phones and also hold it(Check out this article : http://www.uxmatters.com/mt/archives/2013/02/how-do-users-really-hold-mobile-devices.php)
That said, really good work and good luck with design school. On a side note what was the sampling of the user base you evaluated your designs with and how did you choose them?