Complex sentence: Rezső initially had difficulty finding a publisher, mainly due to the unusually depressing and partially political nature of the song, with one potential publisher replying, It is not that the song is sad, there is a sort of terrible compelling despair about it.
Split into simpler sentences: Rezső initially had difficulty finding a publisher, mainly due to the unusually depressing and partly political nature of the song. One potential publisher stated: It is not that the song is sad, there is a sort of terrible compelling despair about it.