Composed between 1955 and 1957, this work is a brilliant example of the post-WWII school of serialist composition. Initiated by the composer's fascination with the spatial distribution of sound as a musical element, the score positions three orchestras, each with its own conductor, around a concert hall, ideally in a semi-circle. The orchestras sometimes perform independently at their own specified tempi, but at other times they will begin to interchange musical information by calls and responses to each other, echoing of material, or coordinating in a mutually shared tempo and pulse. At times musical material may move from one orchestra to another, one orchestra furthering or completing the task of another - "They fall apart or cling together ... one receives the other into itself, and plays with it, extinguishes it ... they become transformed". The composer's aim is to create for the listener a "common time-world" among all the sound, where the music is not contrapuntal points of sound, but groups of combined sounds and noises. But the ensembles can never entirely coalesce, and hence the music is always in flux, moving and dividing. A marvellous palette of timbral combinations and exciting, as well as at times internally lyrical, orchestral images await the listener. ~ All Music Guide
