Brad Paisley has provided vocals and guitar to “Merry Christmas Baby,” a track on Colbie Caillat’s upcoming holiday album. Set for release Oct. 23 on Republic Records, Christmas in the Sand includes her collaboration with Gavin DeGraw on another classic, “Baby, It’s Cold Outside. The project also features several original songs, including the title track written by Caillat, Jason Reeves and Kara DioGuardi. … In related news, Paisley will deliver the first single from his new album to country radio late Thursday night (Sept. 20). The song and album titles, as well as the album release date, have not been announced.