From the back cover:
Hail! Hail! Rock and roll!
It's a powerful Word, and Furfur wants to be its Demon Prince. But to get that coveted title, Furfur is going to have to pull a fast one on all of Hell's elite - including Lucifer himself! And to do that, he'll need all the help he can get...
Night Music is Book One of The Revelations Cycle. In addition to the adventure The Demon Prince of Rock and Roll it has in-depth looks at the Archangel Laurence and the Demon Prince Saminga; two new Superiors (Christopher, Archangel of Children, and Fleurity, Demon Prince of Drugs); expanded rules for Soldiers, Saints and the Undead, and a complete setting: In Nomine Austin, with dozens of NPCs, locations and ideas for divine (or infernal) adventures.