Iannis Xenakis, the Greek-French experimental composer and protege designer for the famous architect Le Corbusier, advanced theories of the vertical “Cosmic” city as the only sustainable way forward. Here, he wrote this essay in 1966, decrying decentralization (read: suburban sprawl) in favor of building up, up, up…5 million inhabitants to be housed in a single megastructure, a hyperbolic paraboloid of more than 3,000 meters high and 50 meters wide.