In the lyrical universe of Oscar Hijuelos' imagination, men and women inhabit a time and place where melody and memory hang thick, like a mid-October Habana haze. The calibrated tika-tika-tikes of a cha-cha recall the deliberate steps of a lover's heels on ceramic tile. Tangos swirl about the most elegant men; rumbas inflame the most wild women. And always, there is a soundtrack. In Hijuelos's latest novel, that soundtrack is a single song, "A Simple Habana Melody". Its composer: a melancholic Cuban whose life and private longings trace the sine curve of notes on a sheet of music. Pulse-quickening hopes. Enervating regrets. A mournful melody for a misunderstood man.