What is the X in X-mas?
cylindrical drum larger and deeper toned than the closely related snare drum and lacking snares. It is usually about 18 inches (45 cm) in diameter and 14 inches (35 cm) in height and is normally beaten with two soft-headed sticks. The heads are tensioned by rope lacings or metal rods. Like the snare drum, the tenor drum descended from the medieval tabor. Though usually associated with military bands, especially since the early 19th century, it occasionally appears in orchestral scores, such as Benjamin Britten's opera The Rape of Lucretia (1946).