We like to think of the "great composers" as God-like creatures who create music purely using their own imagination. But is composition mostly inspiration, or mostly perspiration?
Since March 31st is Joseph Haydn's birthday, his "London" symphony could serve as an example. Haydn composed symphony 104 while on a prolonged visit to England in 1795. The last movement goes like this:
While he worked for the Esterházy family in Eisenstadt, Austria, Haydn became familiar with the music of Croatian peasants in surrounding villages. One of the songs he learned was "Oj, Jelena, Jelena, jabuka zelena", which became the basis for the last movement of symphony 104. Since Haydn included a drone in the piece, he probably had heard the song played at dance tempo on the local "gajde" bagpipe. Below is a guitar version being taught to schoolchildren in Croatian Međimurje by Lidija Bajuk:
Should Haydn have informed his fans about the sources of his music? Written "trad, arranged by JH" on the manuscript? Perhaps offered to share some of the money earned from symphony 104 with the peasants from Eisenstadt?
How would we compare the situation in 1795 with the rights of source communities today?