This site introduces unknown Emanuel Bach (C. P. E. Bach).
ChatGPT4o writes as follows (please note that it may not be accurate):
Emanuel Bachʼs Sonata in B-flat Major Wq. 51-2 (H. 151) is one of the most emotionally rich works among his keyboard compositions. This sonata, while influenced by his father Johann Sebastian Bach, pursues its own unique expression. The first movement begins at a leisurely tempo, with a melody imbued with deep emotion that leaves a strong impression. The following second movement is even more introspective, exuding a melancholic atmosphere. These movements demonstrate Emanuel Bachʼs richness in emotional expression. The final movement, Allegro, contrasts with the previous movements with its lively and bright atmosphere, requiring technical skill and presenting a challenge for the performer. Throughout the entire sonata, one can sense Emanuel Bachʼs musical exploration and his role as a bridge to the Classical era.