Apochrosis was originally composed in 2018 as a clarinet sextet at the request of the Machoire Wind Orchestra. It premiered the same year at the Tokyo Ensemble Contest for Workplace and General Ensembles.
The title Apochrosis is derived from a Greek word meaning "shade " or "nuance. " This piece serves as a sequel of sorts, developing the palette of tone colors I explored in my 2017 work "Hue Circle of Twelve Colors for Clarinet Quintet. "
For publication, the piece was restructured to allow performance by various ensemble types, including mixed 6-8 part ensembles, clarinet ensembles of 6-8 parts, a wind and percussion octet (woodwinds + percussion), and even small wind band configurations.
The optional parts primarily serve to reinforce the musical core of the piece. Notably, Part 5 - while listed as optional - carries an important musical role, so please consider flexible part assignments to ensure balance.
Since the original version was written for clarinet ensemble, it's recommended to maintain a clarinet-centered sound when assembling the instrumentation. If performed with brass instruments, take care with volume balance, and adjust as needed with mutes or dynamic control to preserve the intended color and texture.

Notes on Part Assignments:
- If there is only one flute player, they must play Part 1.
- If there are multiple clarinet players, it is recommended that at least one of them play Part 2 (unless a soprano saxophone is also included).
- In a septet or octet ensemble, if there is only one trumpet player, it is recommended that they play Part 5.

Performance Notes:
- If the music feels lacking in intensity, Part 1 (Flute) at measure 35 may optionally play the upper voice to enhance the buildup.
- If Parts 1 and 2 are being played by Flute/Oboe or Soprano Saxophone, and Part 5 (optional) is included, then at measures 72-73, it is acceptable for only Part 5 to play while Parts 1 and 2 rest for those two measures.
- The cue notes in Part 5 at measures 80-84 should only be played if Part 4 is being performed by Horn. In that case, Part 4 (Horn) should remain tacet during these measures while Part 5 covers the line.

Notation Annotations in the Score:
* 1 If the passage is technically difficult, the dashed-line section may be omitted.
* 2 If no clarinet is available, the tenor saxophone should play the solo up to measure 26.
If the tenor saxophone is also unavailable, any suitable instrument may play the solo instead.
* 3 This section should be performed only if Part 2 is played by flute. (Flute only)
* 4 This section should be performed only if both Part 1 and Part 2 are played by flutes.

(Kento Ishikawa)