If you loved Pentatonix's tribute to Michael Jackson [1] and their Broadway rendition of "Anaconda," [2] get ready to hear those "slay" bells. Last year, the sensational group released a music video for their rendition of "Joy to the World." Let's just say, it's a good way to get a direct injection of that end-of-the-year magic. Prepare to be blown away by the performance above, and then watch their unbelievable take on "Hallelujah." [3]