The Ditty Bops — Abby DeWald and Amanda Barrett — manage to be both quaint and hip, sounding both instantly familiar and startlingly new. Clearly fond of the parlor songs, folk ditties, and light, jazzy swing of the early 20th Century, the duo’s organic, mostly acoustic instrumentation and old-school vibe belie the music’s edginess and eccentricity. On the irresistibly bright and consistently charming Moon Over the Freeway, Mitchell Froom is at the production helm and he augments DeWald’s acoustic guitar and Barrett’s mandolin with just the right touches of piano, accordion, violin, lap steel, and organ. “Let’s go get pierogies at my favorite café, the waitresses are grumpy and their English ain’t so great,” they sing on “Waking Up in the City.” Their fairly straight reading of the Everly Brothers’ “Bye Bye Love” is a perfect showcase for their breezy harmonies and joyful approach. Throughout, their deftly written lyrics are noticeably quirky and stimulating, and they seem just as concerned with the flow and sound of the words strung together as they are with their meaning. “I got a chip on my shoulder and a halo on my head,” they tell us on “Angel with an Attitude.” That’s a pretty apt description for these sunny but sly songsters.