The first systematic grammar, of Sanskrit, originated in Iron Age India, with Yaska (6th century BC), Pāṇini (6th–5th century BC) and his commentators Pingala (c. 200 BC), Katyayana, and Patanjali (2nd century BC). Tolkāppiyam, the earliest Tamil grammar, is mostly dated to before the 5th century AD. The Babylonians also made some early attempts at language description.

The ratio of the eleventh harmonic, 11:8 (551.318 cents; ... In that system (which is the fundamental musical grammar of Baroque and Classical music), the tritone is one of the defining intervals of the dominant-seventh chord and two tritones separated by a minor third give the fully diminished seventh chord its characteristic sound ...