WHY IS THIS COUNTRY DANCING? A One-Man Samba to the Beat of Brazil by John Krich (Simon & Schuster: $22; 319 pp.). "If you listen to my music, you will be saved!" So bossa nova star Tom Jobin tells travel writer John Krich at the beginning of the latter's samba through Brazil's music world, and although Krich isn't exactly saved, having subtitled a previous travel book "Around the World in a Bad Mood," he clearly isn't much interested in redemption. He does manage to tag along on a voodoo-like candomble ritual outside Rio and talk to many of Brazil's musical gods: Milton Nascimento, Gilberto Gil and Caetano Veloso, among others. Krich's attempts to make his prose overtly musical is off-putting at first, but eventually he settles down to a comfortable beat, chronicling the lives and hopes of the people who make up the diverse musical traditions of carimbo (Belem) and revo (Recife), baiao and forro and of course the constant samba of Rio de Janeiro. Krich attends numerous carnival celebrations and provides the obligatory tourist-in-the-Second-or-Third-World observations ("Is Rio really Paris with jungle or Calcutta with beaches?"), but the book comes alive when the author lets the musicians talk about, and the audience sway to, their music. "Where there is dancing, there is hope," reads the graffiti on one dance-hall placard, and that may be the best answer to the question posed in Krich's title.