Trettondag is the Christmas holiday that’s supposed to be the day the Three Wise Men found the baby Jesus, and it’s a traditional part of the Swedish Christmas calendar. And this year, Fasching and Stockholms Bluesförening have marked it out for a very special set of performances. Headlining their Trettondagsblues celebration is legendary Chicago blues musician Larry “Mud” Morganfield, son of, you guessed it, Muddy Waters. He blends performance of his own work with that of his father’s and won a Blues Music Award in 2015 for his Muddy Waters cover album For Pops: A Tribute to Muddy Waters. Also performing are international blues act Trickbag, Umeå’s Headline Bluesband, and country and folk act Felicia Nielsen.