With around two hundred pieces and a total duration of four and a half hours, Georg Kröll's diary is one of the largest piano cycles in music history. And the work in progress that began in 1987 continues to grow. All of the pieces already composed and others that are still possible are based on the basic series of Arnold Schoenberg's Suite for Piano, Op. 25. Schoenberg's series is permuted 42 times. Each note in this permutation, 42 x 12 = 504 notes, becomes the basic and starting note in the sense of a code that generates the material of the piece in question. Right at the beginning of 1987, for example, Kröll wrote the piece Parodia ad A. Sch. based on the starting note 82 in reference to the prelude to Schoenberg's suite. Just as this first purely dodecaphonic work, written between 1921 and 1923, combines the new pitch organization with the old movement types of the French suite, Kröll combines innovation and tradition in his diary through numerous references to music from history and the present.
The composer, born in Linz am Rhein in 1934 and long-time lecturer in composition and music theory at the Rheinische Musikschule Köln, develops an incredible variety of characters from Schönberg's nucleus. As with Beethoven's late bagatelles, these are not entertaining little things, but highly concentrated miniatures lasting from a few seconds to five minutes, which often only use two or three distinctive elements: repetitions, lines, intervals, alternating notes, appoggiaturas, trills, melodies, chords, staccatos, legato bows. The variety of playing styles, tempi and gestures is immediately apparent. In contrast, the serial unity of all pieces seems sublime. For partial performances,
Pianists can make any selection they like, but they should then play the pieces in the order of the ordinal numbers so that the structural principle of the whole is also reflected in the partial cycles.
Kröll initially composed diary entries 1 to 44 in order. He left out only a few numbers and composed them later. Others he preferred, including the aforementioned 82 Parodia ad A. Sch. or 148 Poco Rubato (Laudate Dominum). In 1987/88 alone he wrote 41 pieces, about a fifth of all that he would complete by his 90th birthday in 2024. His choice of code seems arbitrary, but follows clear intentions: on the one hand, Kröll's compositional thinking is sparked by special tone sequences and interval structures; on the other hand, he looks for certain tone sequences that are suitable for the implementation of ideas that have already been conceived. His free handling of the systematically generated sound material follows its own artistic logic in each piece.