Two to the Fifth (Magic of Xanth Series #32) by Piers Anthony
I can't remember the last time I read a Xanth book - I DO remember the first - back in '84 when I was working in Denmark and found them in an English-language bookstore. Fun, (VERY!) light fantasy with a brutal assault of PUNishment for the reader. This one has a bit of a odd angle I can't say I liked - but I might look up a few back stories after reading this... and look for the next when it comes out...
The future of Xanth is in frightful peril. A powerful magical bird named Ragna Roc has embarked on a campaign to become absolute ruler of that mystical realm. Those who swear loyalty to him are spared. The rest are simply disappeared.
So powerful are Ragna’s sorceries that even the Good Magician Humfrey dares not confront him directly. Instead he enlists Cyrus the Cyborg, a handsome half-human playwright with little knowledge of the world, in a stealthy subterfuge. Cyrus must assemble a troupe of traveling players to attract Ragna’s interest. And hidden in disguise among the bevy of beautiful young actresses are the young princesses, Melody, Harmony, and Rhythm, whose magics might just be a match for the evil bird.