Public Television stars Keith and Kristyn Getty, the writers of many modern hymns and carols, swing into town from Ireland for their fifth annual tour. Dubbed Irish Christmas: A Celebration of Carols, the program features the duo along with a band of top-notch instrumentalists who fuse Celtic, bluegrass, Americana and classical music with cultural dance routines and the choral sounds of the holiday. The concert takes place at 7:30 tonight at Severance Hall. Tickets start at $30. (Niesel)