Molly Moon and the Monster Music is the final Molly Moon book by Georgia Byng that was released on the 26th of February 2013.
It is a fun-filled final installment in the best-selling series that includes Molly Moon's Incredible Book of Hypnotism. It finds rock star Molly confronting the powers of a magical coin that plays hypnotic music capable of turning listeners into monster slaves. Molly Moon (an eleven year old) is known and loved for her incredible powers - hypnotism, time travelling, mind reading, morphing, world stopping... But now something seems to have power over her. Not only has it made her a brilliant musician, but it's given her thousands of new fans, all of whom are mesmerized by her. Literally. Only Petula, her pet pug, senses an off-note. Molly-the-Maker-of-Magical-Music is one thing, but Molly-the-Big-Old-Meanie is another - and every day Petula sees her kind owner become more and more horrible. What is going on? And can one determined dog sort it out before Molly becomes truly monstrous?