During the last 20 years of his life, the avant-garde German composer Karlheinz Stockhausen concentrated on completing an ambitious cycle of seven operas, collectively titled “Licht” or, in English “Light.” Each opera was named for a day of the week, and inspired by familiar and obscure world mythologies associated with each day.

The opera titled “Montag” (or “Monday”), for example, is devoted to the Moon and the feminine architype of Eve as the mother of all creation. Two additional main characters that appear in the operas are Michael the Archangel, representing the creative force, and Lucifer, representing the destructive force.

Each opera begins with a “Greeting,” or overture, often an electronic piece designed to be heard in the theater lobby while the audience gathers, and ends with a “Farewell,” sometimes intended for performance outside the theater proper, to be heard as the audience disperses.

Story lines in Stockhausen’s operas draw on many sources, including the composer’s own childhood, and have more in common with symbolic Renaissance courtly masques and pageants than works by Verdi or Puccini, but might be considered a 21th century response to Wagner’s 19th-century cycle of four mythological “Ring” operas.

Portions of Stockhausen’s operas were premiered piecemeal starting in 1977, and only on rare occasions staged in their entirety. The last to be completed, “Sontag” (or “Sunday”) was performed complete for the first time in Cologne, Germany, on today’s date in 2011, more than three years after Stockhausen’s death.