The Sonata No. 1 ("Centaurus") for prepared piano, written in 2010 was composed for the Australian pianist Mark Kruger. The four different registers of the modern concert grand (separated by the cast-iron frame boundary) symbolize the areas of body, heart, soul, and mind (intellect). The lowest 26 keys and strings are the abdomen, which is assigned to the animalistic nature. For the next key zone 22 erasers are used in the strings, which are fixed at the level of the fourth to the seventh overtone. The resulting, bell-like sound symbolizes the area of heart and emotion. Within the "third zone" only the inside piano techniques are used exclusively. Here the player plucks and snaps the strings or uses tremolos. This metallic sound stands for the soul and symbolizes pure spirituality. The last key area reflects the intellect. For this purpose, the keyboard is covered with fabric, creating a choking and percussive sound.
The antagonistic tension within the use of specific areas refers to the sonata form.
Andreas F. Staffel