[3] Hadzidakis was born on 23 October 1925 in Xanthi, Greece, to lawyer Georgios Hatzidakis, who came from the village of Myrthios, Agios Vasileios, in the Rethymno prefecture in Crete; and Aliki Arvanitidou, who came from Adrianoupolis.

[1] He met and connected with other musicians, writers, and intellectuals including George Seferis, Odysseas Elytis, Angelos Sikelianos, Yannis Tsarouchis and especially the poet Nikos Gatsos who became a close friend.

Hatzidakis's first composition was the tune for the song "Paper Moon" ("Χάρτινο το Φεγγαράκι"), from Tennessee Williams' A Streetcar Named Desire staged by Karolos Koun's Art Theatre of Athens.

His first piano piece, "For a Little White Seashell" ("Για μια Μικρή Λευκή Αχιβάδα"), came out in 1947, and in 1948 he set a collection of Gatsos poetry to music: Blood Wedding.

[6] In 1949, Hatzidakis shook the musical establishment by delivering an influential lecture on rembetika, the urban folk songs that flourished in Greek cities, mainly Piraeus, after the Asia Minor refugee influx in 1922.

Putting theory to practice, he adapted classic rembetika in his 1951 piano work, Six Popular Pictures (Έξι Λαϊκές Ζωγραφιές), which was later also presented as a folk ballet.

In 1955 he wrote the score for Michael Cacoyannis' film Stella, with actress Melina Mercouri singing the movie's trademark song "Love that became a double-edged knife" ("Αγάπη που 'γινες δίκοπο μαχαίρι").

He composed the score for the 1955 film Laterna, ftoxia kai filotimo "Λατέρνα, φτώχεια και φιλότιμο" In 1958, Hatzidakis met Nana Mouskouri, his first "ideal interpreter".

[5] Also in 1962, Hatzidakis produced the musical Street of Dreams (Οδός Ονείρων)[8] and completed his score for Aristophanes' Birds (Όρνιθες), another Art Theater production which caused an uproar over Koun's revolutionary direction.