Slon, the Chicago Underground Trio’s third album, is an aural and political statement. Coronetist Rob Mazurek, bassist Noel Kupersmith and drummer Chad Taylor are phenomenal jazz talents interested in technological possibilities (Mazurek and Kupersmith are given instrumental “computer” credits) as well as jazz’s venerable heritage. The trio imbues Slon with a traditional acoustic jazz foundation of impeccable prowess (“Zagreb,” “Sevens”) while exploring occasional electronic jazz flights (the title track, “Palermo”). Politically, the trio calls Slon (Slovenian for “elephant,”) its anti-war album; “Protest” is a visceral, chaotic evocation of its title. It’s an album of power, vision and conviction.