Gregorian Blue Notes was recorded live at a concert of the ensemble officium with the saxophone player Jürgen Seefelder held in Worms Cathedral on July 22, 2001. Its aim is to capture a symbiosis between the timeless and endless chant of the Gregorian chorale and the evanescence of improvisation created in the moment and for the moment, as exemplified by jazz, while preserving the atmosphere needed for this act of creation. Some of the Gregorian chants are overlaid by the saxophonist's improvisations, others are picked up and extended or contrasted with something completely new.