German composer. Georg Andreas Sorge was appointed as organist in Lobenstein at the age of 19 and remained there all his life. He wrote treatises about organ building and pedagogic works including a Clavierübung for organ or harpsichord (in 2 vols. 1739/42); Sorge is best remembered today for his book Vorgemach der mus. Komposition which propounded the tertian structure of chords, a theory that is still used in the teaching of harmony today. Fifteenth member of the Mizler Society (immediately after Bach), Sorge came into bitter controversy with contemporary theorists Marpurg and Quantz. He published a set of little Organ Sonatas l748, twelve further Sonatas "in the new style" c. 1745, a Toccata through the 24 keys, three Fugues on BACH, several Trios and Chorale Preludes.