Aurora Borealis was inspired by the natural phenomenon that occurs in the northern latitudes.  In short, auroral events are caused by the collision of charged particles with atoms in the high altitude atmosphere.  Last year I spent most of my summer playing piano in a rock band aboard a cruise ship that traveled from Seattle, WA to Anchorage, AK and back several times.  During a geomagnetic event late one night, I was fortunate enough to see the Aurora in the distance while sailing from Juneau to Hoonah, AK.  The piece has three main figures: an ascending/descending tetrachord, a repeated eighth-note motive, and a melody (first heard in the clarinet).