The realization was done by Masanori Enoki.

The autograph manuscripts of these unfinished works are held by the Museum of Modern Music, and photographs are also included as an appendix in the Shunjusha New Complete Works.

Composed on November 12, 1916

Autograph Manuscript: Ms. 416

Commentary

The composition year is noted next to the title in the autograph manuscript.

As the name 'Impromptu' suggests, it is written with a very free rhythm. Although the melody is based on 3/4 time, measures such as m. 14 feature a very peculiar rhythm. From these characteristics, it can be inferred that the piece is intended to be played with considerable rubato, rather than strictly adhering to the written note values. The original extends only to the middle of measure 26, adopting an AABA form up to that point. In the realization, an AABAA form is treated as a single section from this point, and a middle section with a completely different character has been created. (Masanori Enoki)

Performance Tips

This piece evokes Chopin's Nocturnes. The left-hand accompaniment ebbs and flows, freely changing note values, starting with quintuplets, then triplets, 16th-note quintuplets, and so on. It would be ideal if both hands could play independently, without being vertically aligned. Do not feel the bar lines; instead, perceive a large wave. From the Meno mosso in the middle section, for eight measures where the left hand sustains the note A, a special moment can be created, as if time stands still, accompanied by the chromatic movement in the right hand. Subsequently, from measure 43, the bass begins to move, gradually becoming broader and deeper.