It’s an acoustic show with style and panache tonight as Fannie Zollicoffer (vocals, guitar) and Melinda Root (vocals, flute, harmonica) present an engaging tour of American roots music, encompassing country, folk, blues and jazz standards, and some original tunes. These talented ladies have very different singing styles: Root has a big voice and has been very influenced by early jazz and blues, while Southern lass Zollicoffer has a sultry twang. But even so, Root and Zollicoffer have an incredible empathy. Their voices blend well in harmony, and on a number of songs they switch off from verse to verse as if they were sisters who’d been singing together all their lives. At 9 p.m. at Iota, 2832 Wilson Blvd., Arlington. Free. (703) 522-8340. (Ken Roseman)