We previously reported that MBC was working on a Christmas special with the ladies of SNSD, and�it's just been revealed that singer Sung Si Kyung will be a guest on the program. The ballad singer will be performing a duet with the girls on 'SNSD's Christmas Fairy Tale', giving viewers a very special holiday treat. SNSD will also be working with�Oh Sang Jin and singer Alex, who will be MCing the MBC special. A representative from MBC had described the program with, "'SNSD's Christmas Fairy Tale' will be a music show with a specific concept. The girls will be able to do all the things they've always dreamed about doing on stage." The program is scheduled to air on December 24th at 12:20 a.m. KST. Source & Image: MyDaily