Hark! The holidays are upon us, and so are the holiday tunes. Who better to join us than a pair of sublime vocalists with soulful new Christmas albums, Samara Joy and Gregory Porter? Together they reflect on the season’s warm and wonderful traditions, as well as a sense of mission behind their glad tidings and good cheer. Meanwhile, Greg and Nate are still arguing over the basic merits of holiday jazz, while taking stock of this year’s new releases.