Part 4 in the Tales series, or the first part of the second Tales trilogy, so to speak. The tales revolve around the holy city of Istar and the Kingpriest, in the period before the Cataclysm. It's got 8 stories, not all equally good or entertaining. Michael William's songs have never been my cup of tea, so I didn't read that one. The others were reasonably good to good (The Silken Threads by Weis & Hickman, Kender Stew by Nick O'Donohoe, Off Day by Dan Parkinson). The Three Lives Of Horgan Oxthrall by Douglas Niles was boring, the way it was written and told.

The Reign Of Istar is not an essential book, it merely offers background stories which you can read after the Kingpriest trilogy, for example. ( )