Aiselin seems like the type of girl who likes classical music and perhaps something akin to what the Celtic Women sing...and you'd be right.
As she would get to know Julian, seeing as she's the fan apprentice for that route, it becomes clear that she grows to have two new favourites...
Shanties and Villain Songs!
Shanties would make sense from the act of Julian once being a part of a pirate crew...but Villain Songs?
That's the dramatic bonus from him too.
But the funny thing is, when Aiselin does sing a villain song, she goes all out. She isn't just singing and acting the villain at that point, she is the villain. And she does it pretty well too...it's almost scary.
(Bonus: Although she can play a heroine role, she can fully pull off a great villain...given she actually auditions for a villain role.)