Here are two free recordings for the Christmas season, both by the U.S. Coast Guard Band Euphonium-Tuba Quartet.
Both are Gary Buttery arrangements from Cimarron Music. Find the sheet music on Cimarron's Euphonium Music Page.
English Folk Christmas (medley)
https://youtu.be/OtLHHUALZM4
Greensleeves (What Child Is This?)
https://youtu.be/3WZetrhCiMY
Merry Christmas!