The former palace of Archduke Charles is today dedicated to music. Like an instrument maker's workshop, the Museum der Wiener Philharmoniker und Haus der Musik (to give it its full name) on the second, third and four floors enliven the building with a multitude of sounds and melodies. On the second floor, explore the world of tone; learn all about the great Viennese masters of music on the third floor; and produce your own compositions at Brain Opera on the fourth floor.