New Folk Acts Worth Listening To: The New Yorker When it comes to "Inside Llewyn Davis," the new Coen brothers movie, I'll respectfully leave the critical work to my colleagues Anthony Lane and David Denby, except to say that the movie's appreciation of its great subject - the folk-music scene in Greenwich Village in the period just before Bob Dylan's arrival - is wry, but full and soulful. Inspired by Dave Van Ronk's wonderful memoir, "The Mayor of MacDougal Street," and many other sources, the Coens have their fun about the scene, but their love for the music - the depth and variety of it - could not be more evident. Last night at Town Hall, the Coens and their colleagues put on a kind of promotional concert, called Another Day, Another Time, for the film. It featured big-name acts (Elvis Costello, Keb" Mo," Jack White, Patti Smith, Marcus Mumford) all performing at their earnest best; a folk icon, Joan Baez, proving that a voice challenged by time does little to diminish her presence and spirit; and some folk-music wizards - the Punch Brothers (led by the mandolin genius Chris Thile), the Avett Brothers, Gillian Welch, and Dave Rawlings - who formed the backbone of the night. But what gave the evening its dynamism, its joy, was its sense of discovery. I may be way behind the curve here, but a few acts - the Milk Carton Kids, Rhiannon Giddens, and Lake Street Dive - were new to me, knocked me flat, and ought to be passed along. The Milk Carton Kids, the best known of the three acts (they've been on "Conan" and "A Prairie Home Companion"), are the duo of Kenneth Pattengale and Joey Ryan, and they are anchored by a rolling Dave Rawlings-like guitar style and harmonies out of the Everly Brothers; here, they are playing their song "New York": Rhiannon Giddens, who often fronts a band called Carolina Chocolate Drops and plays fiddle and banjo, took the stage in a cherry-colored gown and just sang, first a country song, then one in Gaelic. During the intermission, someone told me there were scouts in the audience looking to book new, young acts. I can't imagine, then, that Lake Street Dive, a quartet led by an amazing young singer, Rachael Price, won't be getting some air time soon. Here, the group plays "I Want You Back" on the sidewalk - Amy Winehouse by way of Michael Jackson, but totally new: And here is the song that the quartet played last night, "You Go Down Smooth," as the band performed it in the studios of WFUV, a radio station that is a kind of salvation for folk music, old and new, and broadly defined. The old, weird America lives. Above: The singers Gillian Welch, left, and Rhiannon Giddens, center, with the actress Carey Mulligan, from "Inside Llewelyn Davis." Photograph by Evan Agostini/Invision/AP.