Dropout kara no Saishuushokusaki wa, Isekai no Saikyou Kishidan Deshita

Violinist Masumi Todo gave up her dreams of becoming a professional musician after failing at an international competition. Despite her disappointment, she kept playing the violin. One day she accidentally falls down a flight of stairs and finds herself lost in another world. In the midst of her confusion, she is captured, accused of espionage, and forcibly taken to the Knight Commander Arc to explain herself. Caught in a desperate situation, Masumi's destiny will be illuminated by the “violin” that has come to the other world with her… (Source: Qurie, translated)