Manolis Hadjidakis was born in Heraklion, Crete in 1909, and became a famous Greek composer, though he was not a composer of Rebetiko. He studied at the University of Athens, where he graduated in 1933 and took his PhD in 1942. On 31st January 1949 he gave the famous “Hatzidakis 1949 Lecture about Rebetiko” at the “Art Theatre”, which included performances by Markos Vamvakaris and Sotiria Bellou. I don’t know if these performances were recorded.