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 A minor Wq. 50-03 (H. 138) is one of the works that showcases his unique musical style. This sonata consists of three movements, each with a different tempo and emotion. The first movement is characterized by its rapid and energetic motion, drawing the audience in with its strength. The following second movement has a leisurely tempo, evoking deep emotions and an introspective atmosphere. The final third movement requires a calm and pure expression, balancing the entire piece. This sonata not only demonstrates Emanuel Bachʼs creativity and sensitivity but also reflects how his music served as a bridge to the Classical era.