Scholarly and scientific study of music. In the late 18th and early 19th centuries, such study was done by amateurs such as Ludwig von Köchel. As interest in earlier music grew, greater professionalism was required, including the ability to decipher and assess musical manuscripts and historical documents. Musicology's first great monument was the first edition of Johann Sebastian Bach's complete works (1851–99). The scope of musicology may be summarized as covering the study of the history and phenomena of music, including (1) form and notation, (2) biography, (3) the development of musical instruments, (4) music theory (harmony, melody, modes, etc.), and (5) aesthetics, acoustics, and physiology of the voice, ear, and hand. In recent decades music theory has again become a separate specialization.