Another interesting source is The Singer of Tales, by Albert Lord. Trying to understand Homer by studying oral epic poems from the Balkans, collected in the 1930s
Milman Parry (1902-1935), an American scholar, developed the theory that the Homeric poems are oral poetry, and learned Serbo-Croatian in order to study living oral poets and understand how they learned and practiced their craft. Albert Lord was his assistant. Parry died at the age of 33 from an accidental gunshot and Lord continued his work. Parry's son Adam Parry later published a collection of his father's writings on Homeric poetry.
Adam Parry also died young (motorcycle accident).
I heard Lord lecture when I was a student. Besides The Singer of Tales and other writings on oral poetry, he also wrote Beginning Serbo-Croatian. I think he also learned Albanian to study the oral poetry in that language too.