Set in the Vienna of the future, a time where the evil Emperor Thaddeus Vent has banned all music from the home of Johann Strauss, and any instruments found are to be removed from the city forthwith. But the Emperor's old piano, Oscar, is on the run and teams up with a set of other rogue instruments (a triangle, a harp, a violin etc) and a human friend in the battle to bring the sounds of music back to Vienna.