On the way to their guesthouse in Vienna, the Mozarts witness a terrible incident in which the arrogant son of a nobleman mistreats an old woman and her grandchildren. Outraged, Amadeus challenges the man to a duel – "whip against violin." He deliberately plays the violin badly so that the horse of the evil young man runs away. News of this incident quickly spreads around Vienna. Amadeus gets to know two young street musicians and joins them to form a trio, playing in the music cafes of Vienna. However, neither the humiliated son of the nobleman nor Devilius and his sidekick Monti want to give up.