Vulfpeck

Anonymous 4, the New York-based a cappella group best known for performing medieval music, is touring in farewell concerts. (Courtesy Dario Acosta)

Oct. 19-20: Anonymous 4, Passport, Fuzz, Slash, Borodin Quartet, Vulfpeck

SUNDAY, OCT. 18 Anonymous 4: The acclaimed cappella group’s farewell season program…