Between 1977 and 2003, Karlheinz Stockhausen composed LICHT, light, a cycle of seven operas named after the days of the week. Together they last about 29 hours. The whole cycle is built on a single superformula of three melodies, one for each of the central characters, Michael, Eva and Luzifer. The formula defines the tonal centers and the durations of whole scenes. Each opera is composed from an elaborated form of its own day’s part of the formula.