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. 65-20 (H. 51) is one of the particularly captivating works among his keyboard music. This sonata, while influenced by his father Johann Sebastian Bach, possesses its own unique expressiveness. The first movement begins with lively and energetic motion, drawing in the audience with its strength. The following second movement is characterized by deep emotion and delicate expression, offering a glimpse into Bachʼs inner world. The final third movement provides a light and rhythmic finale, bringing the entire piece to a brilliant close. This sonata is an excellent example of Bachʼs innovation and sensitivity during the transition to the Classical period, allowing one to enjoy his musical diversity.