In the Special School in Leicester I worked at, Singing together was a regular, with the deputy head on the piano, the rest of us got a free lesson, bless you Dereck. Circa 1980 a christmas favourite was

Wrapped in swaddling clothes, the baby's lying
In his mother's arms, there'll be no crying
Shepherd's from afar, they do come [nigh?] him
Rocky Road-um, heyyy, a Rocky Road-um.

Rocky Rocky Road, a Rocky Road-um
Rocky Rocky Road, a Rocky Road-um
Rocky Rocky Road, a Rocky Road-um
Rocky Road-um, heyyy, a Rocky Road-um.