This site introduces unknown composer Emanuel Bach (C. P. E. Bach). This English version was translated from Japanese one by ChatGPT.
ChatGPT4o writes as follows (please note that it may not be accurate):
Emanuel Bachʼs “Alla Polacca in B Minor Wq. 113-7 (H. 199)” is a work that stands out for its wide range of emotions within his keyboard music. While based on the rhythm of a polonaise, the piece is imbued with Bachʼs characteristically expressive style. The key of B minor lends a deep shadow to the entire composition, leaving a strong impression on the listener. The melody often unfolds in unexpected directions, surprising the audience. Ornamentations and sudden changes in dynamics bring tension and vitality to the music. The improvisational elements present in Bachʼs works are vividly reflected in this piece as well. It is said that the emotional expression in his music influenced later Romantic music.