The Famous Piraeus Quartet

I Tetras i Xakousti tou Peiraios (Τhe Famous Piraeus Quartet )
was formed in 1934 by Yiorgos Batis, Markos Vamvakaris, Anestis Delias, & Stratos Pagioumtzis.
They played in more legitimate clubs and taverns, becoming extremely popular,
and made many famous recordings, despite the notority rebetiko had. Enjoy here: https://www.behance.net/gallery/93405693/The-Piraeus-Quartet