Evidenced by the success of the Pitch Perfect movie franchise, the new Broadway musical In Transit, Texan pop quintet Pentatonix and reality competition shows like The Sing-Off and Pitch Slapped, a cappella is back with a vengeance. Few organizations are prouder of this resurgence than the Barbershop Harmony Society, a Nashville-based troupe boasting more than 23,000 members that range in age from 8 to 100. Formed in 1938 (as the Society for the Preservation and Encouragement of Barber Shop Quartet Singing in America) and now billed as “the world’s largest all-male singing society,” BHS is set to invade downtown San Antonio for its annual Midwinter Convention. Extending its scope by bringing women’s choruses and male/female ensembles into the fold, the program kicks into full swing Thursday afternoon with a keynote address from Deke Sharon (aka “The Godfather of Modern A Cappella”), a vocalist, arranger, composer and producer with a knack for simulating the sounds of musical instruments with his voice. Beyond classes, meetings and rehearsals, the five-day affair includes a number of public events hosted at the Lila Cockrell Theatre (610 E. Market St.), including a Thursday Night Show uniting the groups AISQC, Boardwalk, Pratt Street Power, The Buzz, Main Street, Signature, Four Voices, Forefront, Keepsake and the Children’s Chorus of San Antonio ($65, 7:30-10pm Thu); Friday’s Youth & Seniors Chorus Festival showcasing 25 ensembles from across the country ($50, 11am-10pm Fri); an International Seniors Quartet Championship between Social Insecurity, Armchair Chorderbacks, Velvet Frogs, Leftover Parts, Time Bandits and 20 other groups ($50, noon-5pm Sat); and — likely the most anticipated of them all — a Saturday Night Show boasting a “world-class entertainment lineup” combining award-winning acts, international youth choruses and MacArthur High School’s own a cappella group PFC ($65, 7:30-10pm Sat). Further proof that this classic American tradition is hitting a high note — all of Midwinter’s ticketed events are on the verge of selling out. For details and tickets, visit barbershop.org/sanantonio.