If her tank/gunship is destroyed, Nonon reveals the ultimate form of her Symphony Regalia, which the rest of the student body describes as her "encore". The remains of her vehicle transform into a tower-like stage, from which Nonon emerges in a pink drum-major uniform with a tall, horned hat. Its primary weapon is a cannon on the hat which releases devastating purple energy beams to the sound of Beethoven's Symphony No. 5: "Fate". The music's rhythm resonates with the targeted Life Fibers of her opponent, manipulating them and inflicting damage at the same time, making it effectively impossible to move when blasted by the music.
Taken from: http://kill-la-kill.wikia.com/wiki/Nonon_Jakuzure