About the Piece

Approaching my 50th birthday, I reflected on my "upbringing" and strongly reaffirmed the profound significance of the accumulation of numerous inevitable and accidental events (which are, indeed, still ongoing). Concurrently, this reflection became an opportunity to re-examine "what changes" and "what remains constant": myself, constantly influenced and "changing" (or having changed) through various phenomena and encounters, and myself, "unchanging" and difficult to alter, bound by innate personality and inclinations.

The title "AESTUS" (pronounced 'aestus') is a Latin word meaning "flame" or "wave" (or "heat," "surge," "passion," "fury," etc.). However, this piece does not attempt to depict these aspects sonically; rather, it merely translates the fundamental compositional idea into words. This idea shares commonalities with a woodwind quintet and a piano solo piece I wrote about 22 years ago (this current piece is the second solo piano work since then). While my creative consciousness and approach have naturally evolved since those earlier works, the challenge of pushing this idea further has always lingered in my mind. Both "flame" and "wave," though single phenomena, possess constantly fluid forms. The title serves not only as a word representing a compositional idea but also as a symbol for the changing and unchanging aspects of my own creative work over the past two decades, which form a part of the aforementioned "upbringing."

The piece is constructed by combining multiple fragments ranging in length from a minimum of 1.1 seconds to a maximum of 51 seconds. In creating these fragments, seven types of materials with the following external characteristics were used, either individually or combined, designated as "main materials" or "sub-materials" based on their prominence and frequency of use within the fragments:

• Continuous phrases (repeated notes)
• Continuous passages (pitch changes)
• Segmented phrases (repeated notes)
• Segmented passages (pitch changes)
• Short-duration long tones (repeated notes)
• Short-duration long tones (pitch changes)
• Long-duration long tones (sustained pitch)

The aforementioned materials appear accompanied by secondary elements such as "appoggiaturas," "large leaping figures," and "chordal forms" at specific intervals. Furthermore, the choice of which of the eight designated registers to use is strictly applied, and the combinations of "main materials" and "sub-materials" are arranged to ensure all are distinct.

Regarding pitch elements, the notes "A," "E," and "E-flat" (Es) are derived from the first three letters of "AESTUS" respectively, and these three notes are positioned as the dominant pitches for the entire piece. Multiple pitch rows are then constructed around these three core notes, imposing limitations both horizontally (as central notes of phrases, passages, and fragments) and vertically (as sonic bodies).

By arranging and transforming these materials and various elements according to specific rules, diverse aspects of "change" and "repetition" are interwoven within the flow of time at a single tempo (♪=126), thereby attempting to create a unified musical expression.