A new crop of musicians in L.A., including the Dustbowl Revival and Vaud and the Villains, are embracing the low-tech sounds of the '20s and '30s.A nine-piece band replete with tuba, washboard, accordion, fiddle, mandolin, trumpet and guitar joyously pumped out early 20th century standards such as "Nobody Knows You When You're Down and Out," Muddy Waters' deep blues and original tunes that would have sounded utterly at home within the hallowed confines of Preservation Hall in New Orleans' French Quarter.