National High Magnetic Field Laboratory
Magnet Academy: Barkhausen Effect
The Barkhausen effect makes the concept of magnetic domains audible (if not exactly music to the ear).
National High Magnetic Field Laboratory
Magnet Academy: Diamagnetism and Paramagnetism
Think iron, nickel and other "ferromagnetic" substances are the only ones with magnetic properties? In fact, everything reacts to magnetic fields in some way.