Following the world première on October 16th 2004 of LICHT-BILDER (LIGHT PICTURES), the last scene Stockhausen composed of his work LICHT (LIGHT), The Seven Days of the Week – 29 hours of music which he started 27 years ago, in 1977 – Stockhausen began the work KLANG (SOUND), The 24 Hours of the Day.

The Art Foundation Art ache of the Milan Cathedral awarded the commission for PRIMA ORA (ERSTE STUNDE / FIRST HOUR) for organ (or synthesizer), soprano, tenor. The work will have its world première on 5. 5. 05 (Ascension Day) in the Milan Cathedral. (Information: info@artache.it)

Stockhausen continues to experiment with composing music in different, simultaneous tempi. In ERSTE STUNDE (FIRST HOUR) of KLANG, the two hands of the organist constantly play in different tempi: an initial step in rhythmitizing the one-dimensional musician two-dimensionally.