@Ghostwolf2022 her music is actually just how she tunes out her own suffering. Just like Olivia, the operations and training used to make her were excruciatingly painful and she was tortured near daily until she was operational, and after that she was trained by Priscilla like most Sister Models Post-5. Music was her way of dissociating. every Weapon Sister has a dissociation tactic. for Priscilla it was a form of intense Stockholm Syndrom as well as her Sadistic love of causing pain.. as well as her evolving her originally not-combat oriented abilities out of fury and trauma . For Alicia, Weapon Sister 1, it was caring for her other sisters and finding a way to use nurturing others to keep her sanity and humanity. For Olivia it was watching and learning from Alicia, and then a combination of other reasons.. now Ben is her coping mechanism. He's like her security blanket, and if wasn't for Ben buying her a stuffed unicorn, she'd have to hug him every night to get to sleep. For Elenor, pure control and authority is her cope. Being the student body president, holding the authority over who lives and dies during the cullings that happen in the school allows her to dissociate. Beat and Liv are some of the few who arguably found healthier ways to cope.. because Music is beautiful and results in helping the mind grow and Ben is a good person who is a good influence on Olivia, showing her what it means to be a person who helps others as well as a semblence of being a normal person.