Thanks to Middlebrow for informing me that Psalm 98 is a traditional Christmas psalm, despite the fact that it mentions neither Santa Claus nor Christmas shopping - nor Christ, except in eager anticipation.
1 Sing to the LORD a new song, 
       for he has done marvelous things; 
       his right hand and his holy arm 
       have worked salvation for him.
2 The LORD has made his salvation known 
       and revealed his righteousness to the nations. 
3 He has remembered his love 
       and his faithfulness to the house of Israel; 
       all the ends of the earth have seen 
       the salvation of our God. 
4 Shout for joy to the LORD, all the earth, 
       burst into jubilant song with music; 
5 make music to the LORD with the harp, 
       with the harp and the sound of singing, 
6 with trumpets and the blast of the ram's horn— 
       shout for joy before the LORD, the King. 
7 Let the sea resound, and everything in it, 
       the world, and all who live in it. 
8 Let the rivers clap their hands, 
      Let the mountains sing together for joy; 
9 let them sing before the LORD, 
       for he comes to judge the earth. 
       He will judge the world in righteousness 
       and the peoples with equity.