The unpersuasive narrator-hero of this arch, eager-to-please mystery debut is John Field, supposedly a renowned piano virtuoso also famous for his amateur detection. Here, Field goes to play at a Florida music festival in ""Fun City"" (Miami, presumably)--and witnesses the shooting, mid-concert, of N.Y. journalist Sherrill Thorne, ""the foremost music critic in the nation."" At first the culprit seems obvious: a Marielito hit man is killed while fleeing the scene. But things get more complicated when it's revealed that Thorne was already dead, strangled in his box seat, before he was shot! So attention turns to assorted suspects in the ritzy concert audience, which just happens to include: Thorne's sister-in-law, who blames him for her sister's death; victims of Thorne's criticism; etc. Or could the murders (another concert-goer is soon pushed into a crocodile canal) be connected to the festival's featured composer--legendary, muchmarried Antonio Saul Yera, an old man with a cartoonishly colorful past? The solution is an outlandish one, modeled on Agatha Christie, but executed without a fraction of Christie's skill. Equally inept are Higgins' attempts at comedy--which range from real-estate sit-com to cutesy names (pop-singer Lullio Gelasius, police-chief Lorenzo DaPonto, etc.). And despite hard-working musical details (including pedantic footnotes), the music-world milieu is a-clang with wrong notes--among them hero Field, alleged genius and bona fide twit. Thin, talky, amateurish--but, thanks to a certain naive zest, not entirely unpromising.