Carol

Carol is the tale of a teenage girl whose life seems normal enough until she notices music disappearing from all around her, such as the sound of Big Ben, her father`s cello-playing, and the concert of her favorite band, Gaball Screen. After hearing some mysterious voices, Carol is transported to a fantastic world where she must fight against the evil monsters who are stealing the music from Earth. She meets and is assisted by three dashing heroes: Clark, Tico, and Flash.

(Source: AniDB)