Good Morrow to Your Night-Cap is a traditional double jig in D major, two parts, AABB. The title comes from a comic song refrain, printed in the Universal Songster (1834) with a verse about riding out to bid good-morrow to your night-cap, and the phrase attached itself to several unrelated melodies, so the name and its variants turn up in the 19th-century collections on tunes in different keys, meters, and traditions. This version of the tune appears in Ryan’s Mammoth Collection (Boston, 1883, p. 91) and, shortened to Night Cap Jig, in Old Time Jigs and Reels for the Violin (Oliver Ditson Company, 1906, p. 19).
Note: Distinct from The Night Cap in Dance Music of Ireland.