WITH 10 albums and 22 international tours under its belt, beloved music group Cantoamérica this weekend will celebrate 25 years of creating original Central American music for its adoring fans.The group will perform Oct. 22 and 23 at 8 p.m., at the Melico Salazar Theater in downtown San José, joined by popular Costa Rican musical figures Editus, Manuel Obregón, Walter Flores, María Pretiz, Humberto Vargas and Blues Latino, who will pay homage to the pioneering group with a variety of covers.Tickets cost ¢1,500-4,000 ($3.10-8.25), and are available at the theater box office (257-6005).