Ireland’s Keith and Kristyn Getty, writers of modern hymns and carols, are celebrating Christmas with their fourth annual tour of “Joy — An Irish Christmas.” The Gettys are joined by their band, which fuses Celtic, bluegrass, Americana, and classical music. Carnegie Hall, Stern Auditorium / Perelman Stage, 881 Seventh Ave. at 57th St. Dec. 11, 7:30 p.m. Tickets are $15-$150 at carnegiehall.org.