This site introduces unknown 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 Fantasia is characterized by its free form and improvisational elements. His Fantasias pursue changes in emotion and a wide range of expression, including bold modulations and rhythmic changes that surprise the listener. In particular, his Fantasias demonstrate the exploration of new musical expressions during the transition from Baroque to Classical music. These works demand high technical skill and interpretative ability from the performer, leaving a deep impression on the audience. Emanuel Bachʼs Fantasias embody his innovative musical style and have greatly influenced later composers.