Thunderwalker is built on two overlapping edifices. The first encompasses the form of each movement: the first movement is a fugue, the second is a ground bass (passacaglia), and the third is a scherzo-trio. The second abstract structure is derived from what the title suggested to me. I see a thunderwalker as a huge god-like figure who lives in the sky and whose footsteps fall loudly among the clouds. If I were a member of a pre-modern earth society and wanted to get the god-like figure's attention, I would go through a ritual cleansing ceremony (movement 1), then invoke him over and over again (movement 2) until I had summoned him (movement 3). -S.G.