This site introduces unknown Emanuel Bach (C. P. E. Bach).
This piece is an arrangement for solo keyboard of the Sinfonia for orchestra, Wq. 173 (H. 648).
ChatGPT4o writes as follows (please note that it may not be accurate):
Emanuel Bachʼs Sinfonia in G Major Wq. 122-01 (H. 45) is a work that showcases his unique musical style. This symphonia consists of three movements, each possessing distinct emotions and energy. The first movement is characterized by lively rhythms and bold melodies, drawing the audience in with its strength. The following second movement exudes a calm and introspective atmosphere, expressing deep emotions. The final third movement unfolds with light and bright music, possessing a refreshing quality that is fitting to conclude the piece. This work reflects Emanuel Bachʼs diverse expressiveness and his innovative approach that bridges to the Classical era.
For each piece in Wq. 122, explanations are provided in "C. P. E. Bachʼs Posthumous Collection of Keyboard Pieces Wq. 122".