are no surviving copies of the Natya Veda. There are scholars who believe that it may have been written by various authors at different times. The most authoritative commentary on the Natya Shastra is Abhinavabharati by Abhinava Gupta. While much of the discussion of music in the Natyashastra focuses on musical instruments, it also emphasizes several theoretical aspects that remained fundamental to Indian music: Establishment of Shadja as the first, defining note of the scale or grama. Two Principles of Consonance: The first principle states that there exists a fundamental note in the musical scale which is Avinashi (अविनाशी) and Avilopi (अविलोपी) that is, the note is ever-present and unchanging. The second principle, often treated as law, states that there exists a natural consonance between notes; the best between Shadja and Tar Shadja, the next best between Shadja and Pancham. The Natyashastra also suggests the notion of musical modes or jatis which are the origin of the notion of the modern melodic structures known as ragas. Their role in invoking emotions are emphasized; thus compositions emphasizing the notes gandhara or rishabha are said to be related to tragedy (karuna rasa) whereas rishabha is to be emphasized for evoking heroism (vIra rasa). Jatis are elaborated in greater detail in the text Dattilam, composed around the same time as the Natyashastra. China Most guqin books and tablature written before the twentieth century confirm that this is the origin of the guqin, although now it is viewed as mythology. In Chinese literature the guqin dates back almost 3,000 years, while examples of the instrument have been found in tombs that date back to about 2,000 years ago. Although the ancient literature states its beginnings, the origin of the guqin is still a subject of debate over the past few decades. Greece Ancient Greek musicians developed their own robust system of musical notation. The system was not widely used among Greek musicians, but nonetheless a modest corpus of notated music remains from Ancient Greece and Rome. The epics of Homer were originally sung with instrumental accompaniment, but no notated melodies from Homer are known. Several complete songs exist in ancient Greek musical notation. Three complete hymns by Mesomedes of Crete (2nd century CE) exist in manuscript. In addition, many fragments of Greek music are extant, including fragments from tragedy, among them a choral song by Euripides for his Orestes and an instrumental intermezzo from