After finishing the immense cycle Light, one opera for each day of the week, Karlheinz Stockhausen began the unfinished cycle Klang, one work for each hour of the day. Musica Sacra opened in 2007 with the fourth hour, Himmels-Tür for percussionist and wooden door. This year it will sound the first hour, Freude for two harps. It is a paraphrase of three quarters of an hour on the 24 verse lines, one ‘moment’ each, of the Veni Creator Spiritus. Excerpts from it are also sung. Veni Creator is a Pentecost hymn, but is also sung at two decisive moments of choice in human life: marriage and monasticism.