The orthography of the Greek language ultimately has its roots in the adoption of the Greek alphabet in the 9th century BC. Some time prior to that, one early form of Greek, Mycenaean, was written in Linear B, although there was a lapse of several centuries (the Greek Dark Ages) between the time Mycenaean stopped being written and the time when the Greek alphabet came into use.

Early Greek writing in the Greek alphabet was phonemic, and different in each dialect. Since the adoption of the Ionic variant for Attic in 403 BC, however, Greek orthography has been largely conservative and historical.

Given the phonetic development of Greek, especially in the Hellenistic period, certain modern vowel phonemes have multiple orthographic realizations:

This affects not only lexical items but also inflectional affixes, so correct orthography requires mastery of formal grammar (as in French), e.g. η καλή /i kaˈli/ 'the good one (fem. sing.)' vs. οι καλοί /i kaˈli/ 'the good ones (masc. pl.)'; καλώ /kaˈlo/ 'I call' vs. καλό /kaˈlo/ 'good (neut. sing.)'.

Iannis Xenakis (Greek pronunciation: [ˈʝanis kseˈnakis], Greek: Γιάννης Ξενάκης) (May 29, 1922 – February 4, 2001) was a Greek composer, music theorist, and architect-engineer. After 1947, he fled Greece, becoming a naturalized citizen of France. He is commonly recognized as one of the most important post-war avant-garde composers. Xenakis pioneered the use of mathematical models in music such as applications of set theory, stochastic processes and game theory and was also an important influence on the development of electronic music. He integrated music with architecture, designing music for pre-existing spaces, and designing spaces to be integrated with specific music compositions and performances.

Among his most important works are Metastaseis (1953–4) for orchestra, which introduced independent parts for every musician of the orchestra; percussion works such as Psappha (1975) and Pléïades (1979); compositions that introduced spatialization by dispersing musicians among the audience, such as Terretektorh (1966); electronic works created using Xenakis's UPIC system; and the massive multimedia performances Xenakis called polytopes. Among the numerous theoretical writings he authored, the book Formalized Music: Thought and Mathematics in Composition (1971) is regarded as one of his most important. As an architect, Xenakis is primarily known for his early work under Le Corbusier: the Sainte Marie de La Tourette, on which the two architects collaborated, and the Philips Pavilion at Expo 58, which Xenakis designed alone.