I know it's been a while since this thread was active, but I came across it via a Google search on something you might find interesting! According to Wikipedia:

'"Warszawa" is a mostly instrumental song by David Bowie, co-written with Brian Eno and originally released in 1977 on the album Low...The mysterious lyrics and the piece of melody in the middle part of the song are based upon a recording of "Helokanie" by Polish folk choir Śląsk.'

https://www.youtube.com/watch?v=9Gy94N_mcWs