Gladys & Maybelle - Texas Songbirds: Along South Congress at South by Southwest, 2013

From their Facebook Page:

Biography

Gladys and Maybelle are Texas bred songbirds who have been singing in the Stockyards since August 2010 when they took to the streets to raise money for their yearly voyage to Elvis Week, Memphis, Tennessee. After the warm Fort Worth welcome they continued on with their act, incorporating favorite old-school country songs into their repertoire. They have since written and recorded "Memphis Cash", a full length album of original songs. This singing duo is not hard to spot in their colorful, vintage dresses and pillbox hats. You can hear these two sisters most weekends singing their sibling harmonies and adding to that special magic that can only be found in the Fort Worth Stockyards.