Cipher 11: Musical mayhem

This cipher again is separated into two parts, namely an audio file and the following ciphertext.

ZKIGPWQ SLZSIIJ PBJRQKI TIMFTBE PEIVCNP
CVHFEHA OAXINDB PTGDPUO PSJRBEP ZAAAAAA

Unless you’re pitch perfect, you might also find this useful:

I’ll leave you to work out the significance of all this. Once again, the password for the secret area is purely lower-case.