The biggest Chicago jazz story of the year so far is the release of the first CD by the Latin-jazz-fusion nonet Chevere–an event a quarter century in the making. Costa Rican drummer Alejo Poveda, a veteran of a dozen or more local jazz bands, formed Chevere here in the late 70s as a small percussion ensemble; even today his occasional interludes with ace percussionists Ruben Alvarez and Joe Rendon are the high points of Chevere’s sets. The band quickly acquired a full instrumental armamentarium and a cadre of the city’s finest jazz sharpshooters, including reedman Steve Eisen, bassist Eric Hochberg, and piano and harmonica wizard Howard Levy. Mark Ohlsen’s trumpet, along with Chris Cameron’s electric keyboards, help Chevere wallpaper the room with big ensemble textures, and Ernie Denov’s slash-and-burn guitar playing connects the band as much to Carlos Santana as to Mongo Santamaria and Tito Puente. The group began recording its debut CD in 1995, but it took years of coordinating busy schedules to finish the album; this weekend’s gigs celebrate the release of Secret Dream on Levy’s label, Balkan Samba. And despite its protracted, piecemeal gestation, the disc comes pretty close to capturing the charismatic energy Chevere brings to the stage. Fri 1/28, 9 PM, Green Mill, 4802 N. Broadway, 773-878-5552, $12. See also Saturday.