This text presents part of a more extensive study on theory and practice of ethnomusicological fieldwork with camera in Bulgaria between 1953 and 1965. The article seeks to outline one of the first ethnomusicological problems during the digitalization of stored rites and dances recorded without sound cameras and integrated synchronic sound recorders: identification of the sound associated with the footage, the various relations between picture and sound in the every single record, and hence – the possible options for their synchronization in the digitalization process. The paper places the problem in the field of the inextricable connection between the dominant research methodology and the available audio- and filming technologies in the ethnomusicological fieldwork during the considered period, with which it also presents a part of the history of Folk Music Archive at the Institute of Art Studies.