Swamp Dogg at the piano means dancers on the floor at the Folklife Festival. (David Malitz/The Post)

The way the festival is set up, with all of the attractions and tents in straight line down the middle of the Mall, makes it ideal for short-attention span roaming. Walk up the Smithsonian Metro escalator and you’ll be greeted by Soulsville, one of the stages devoted to festival theme Rhythm & Blues. There was outsider-soul minor legend Swamp Dogg, seated at a piano, backed by a funky band, belting out some slightly twisted R&B. His warmup act was fiery blues singer Vera Lee — his nearly 90-year-old mother. As they performed in the quarter-full tent most people sat watching in folding chairs while some couples took to the dance floor to gently spin each other around. (Later tonight, I’d expect a different scene when the Soul Train Dance Party takes over.)

At the Motor City tent, hey, there’s my old college professor (and walking blues/soul/funk encyclopedia) Barry Lee Pearson introducing Motown backing band greats the Funk Brothers! They played on more No. 1 hit songs than the Beatles, Rolling Stones and Elvis Presley combined, he tells us before they hit the stage for the first of two performances of the day.

Over in the Colombian area, there’s a packed tent for the salsa workshop. Dance is also a major element at the Al Son Que Me Toquen Stage, where Don Abundio y sus Traviesos is playing. There will be a demonstration on the dance floor, one of the band members says from the stage. “Music without dance? That's weird. Music and dancing!” he exclaims. A crowd consisting of tourists with fanny packs and cameras and office workers with ties and ID badges looked on. In a shady area off the main strip off the Mall, there are dozens of demonstration booths featuring everything from musical instruments to baskets to coffee.

There’s less of a live-entertainment focus in the Peace Corps-themed section, but Central American group Garifuna Collective played to a packed dance floor — of pre-schoolers who were content to chase each other around and occasionally perk up when there was a burst to the music.

The festival continues through the Fourth of July and picks up again July 7-11.

Previously on the GOG blog: What to eat at the Folklife Festival