This site introduces unknown Emanuel Bach (C. P. E. Bach).
ChatGPT4o writes as follows (please note that it may not be accurate):
Emanuel Bachʼs Württemberg Sonata No. 4 in B minor, Wq. 49-4 (H. 32), is one of the six sonatas dedicated to Duke Carl Eugen of Württemberg in 1744. It is characterized by the deep emotion and shading brought by the key of B minor. The first movement, in sonata form, is marked by a restrained tempo yet maintains a sense of tension, with its contrapuntal treatment and delicate melody leaving a strong impression. The second movement exudes a calm and meditative atmosphere, showcasing typical elements of the empfindsamer Stil. Particularly, the use of ornamentation and subtle harmonic changes provide the piece with rich expression. The third movement is a lively finale, distinguished by its dance-like rhythm and virtuosic passages. This sonata harmoniously combines clarity of form with emotional depth, making it a uniquely captivating work within Emanuel Bachʼs keyboard music. Performances on the [clavichord,] harpsichord, or fortepiano further enhance its rich musicality.