A guess, not an answer. You'll see what everyone else said.
Machine-generated description — written by an image model, not by a person.
Traditional folk ensemble performing on stage, likely Eastern European, mid-20th century. Instruments include accordions, violins, and a drum. Participants wear embroidered folk costumes with aprons and vests. Stage backdrop features faded text ("Zlatni otredi" visible). Black-and-white, suggesting 1950s–1970s.