Johann Carl Friedrich Rellstab was a German composer, writer, music publisher, and critic living in Berlin. Rellstab was a very influential figure in Berlin's musical life. In his youth he studied keyboard with Johann Friedrich Agricola and composition with Carl Friedrich Christian Fasch. He planned to continue his education with Carl Philipp Emanuel Bach in Hamburg, when in 1779 he had to take over the printing business of his father. Given his interest in music, Rellstab changed the focus of the business towards music and added a music lending library (in 1783) and a music publishing branch to the firm (ca. 1785). Later on, Rellstab also made instruments and sold other music supplies.