At LouFest, Carolina Chocolate Drops played at two in the afternoon to an enthusiastic, attentive audience. (This wasn't a surprise: The Durham, North Carolina, trio's old-time string music is a popular draw in St. Louis, and in recent years, it's been playing progressively larger venues.) Banjo, fiddle and clattering percussion buckled together, and the band members took turns in the vocal spotlight; the crooning harmonies and lead melodies were as vintage-sounding as a crackling 78 RPM record. Still, the group is adept at honoring tradition from all eras. Covers of Johnny Cash's "Jackson" and a snippet of Chuck Berry's "Maybelline" — both sure-fire ways of pleasing a local crowd — succeeded.