The UnUrban Irregulars formed just a few years ago to perform at the Unurban Café in Santa Monica, and wound up on the bill at RagFest. Originally a trio consisting of BRAD KAY, MARK FLETCHER and ANDREW BARRETT, this year’s edition also includes TOM MARION, OLLIE STEINBERG and DAVID BARLIA. Festivalgoers will be able to hear them just once this weekend: At Steamers Jazz Club and Café late in the afternoon on April 14, 2012.