If you claim past or present membership in the Flat Earth Society, you could have been part of a youthful psychedelic pop band in Boston during the '60s, or perhaps you feel that gravity and orbiting satellites are part of a vast conspiracy to conceal the truth of humankind's true place at the center of creation. Then again, maybe you're part of an adventurous avant-garde big band from Belgium, particularly that part of Belgium that has historically been known as Flanders. The topography of the Flemish land is truly flat earth of the most literal kind, but some particularly un...