Percy Jackson and the Singer of Apollo (Camp Half-Blood Chronicles, #5.1)

The trouble starts when Apollo introduces Percy and his friend Grover the satyr to the Chryseae Celedones. Three golden women—living statues—appear in front of them, and sing one blissful chord. Apollo has a concert tonight at Mount Olympus, and he needs the Celedones as his backup singers. But there should be a quartet, not a trio—one of the singers has gone rogue. It's up to Percy and Grover to find the missing Celedon somewhere in New York City before she causes any problems. Capturing an attention-seeking automaton in a crowd of mortals is going to require some cagey thinking. Will Percy and Grover succeed, or hit a sour note?