One of the problems of composition that were of particular interest to Serocki was the question of open form. He referred to it for the first time in his piano piece A piacere (and later returned to the problem in Arrangements and Ad libitum). Serocki’s composition is built of three “segments”, with each segment consisting of ten “structures”. The order in which the various structures are performed within each segment as well as the order of performing the segments are at the pianist’s discretion – hence the title of the piece. The composer organized such an “three-part polyvalent form” in a way that would enable the listeners to perceive the whole with their senses and to understand each segment as part of the form. To this end he shaped all parameters of the music (e.g. pitches, duration, articulation) in an appropriate manner and, above all, gave a suitably different expressive “character” to each segment. As he explained,
Each segment uses the same “material pool”. The pool encompasses the entire scale of a concert piano (...), which is used twice in each segment. Thus in each segment we have 88 different pitches (7x12+4), with each pitch appearing twice
[K. Serocki, Chance der offenen Form (Analysen), unpublished typescript, 1976, p. 4.]
The first segment is “sarcastic and playful” in nature, varied in terms of dynamics, full of rapid pitch changes and smooth in its course. The second is “lyrical and levitating” – with muted dynamics, it progresses slowly and calmly and the structures used in it are separated by fermatas enabling the notes to resound to the full. The third segment is “nervous and brutal”, and is characterized by considerable sound density, while rhythm and articulation undergo constant changes.
There is a multiplicity of the forms of the piece – limited only by the principles of combinatorics (3! (segments) x 10! (structures) = 3,628,800 possible sequences), which does not interfere with its “characterological” identity, clear to the listener.
Serocki’s A piacere was played for the first time at the 1963 Warsaw Autumn by an outstanding interpreter of new music for the piano and a composer, Frederic Rzewski.