AND you thought the Jay-Z/Beatles “Gray Album” mash-up was something. Try mixing American jazz with traditional Mongolian music. It’s what veteran trombonist Roswell Rudd did – and the results are simply otherworldly. Rudd and Badma Khanda’s Mongolian Buryat Band recorded an album, “Blue Mongol,” last year, and tomorrow night at 8:30 they take the Zankel Hall stage (at Carnegie Hall). If you want to hear something different, here’s your chance. The wordless singing of Badma Khanda alongside Rudd’s Dixielandish playing recalls swinging Negro spirituals, while the Central Asian acoustic sound gives new meaning to the term roots music. In addition to vocalist Badma Khanda, the Mongolians performing with Rudd include Battuvshin Baldantseren throat-singing and playing the limbe (flute) and khalkh (horse-head bass), Javkhlan Erdenebal on the morin khur (horse-head fiddle), Urantugs Jamiyan on the yatag (zither) and Kermen Kalyaeva playing dulcimer. Tickets are $30-$42. Zankel Hall, 154 W. 57th St.; (212) 247-7800.