A New Dial

Verse 1 refers to God, rather transparently.

Verse 2 refers here to the Old and New Testaments. "Lily white" may refer to purity; at any rate, holly and ivy are usually male and female symbols in pagan lore, so "lily-white boys" as holly & ivy seems unlikely.

Verse 3 does appear to mean the Trinity.

Verse 4 are the Evangelists in both songs.

Verse 5 may have been "senses" and become "symbols."

Verse 6 refers in the new dial to the 6 days of Creation in the Book of Genesis; the reference to "work" may have become "walkers."

Here is where things get interesting:

Verse 7 here refers to the liberal arts of the 13th century scholastics: the "trivium:" grammar, rhetoric and dialectic, and the "quadrivium:" arithmetic, geometry, astronomy and music. Owing to the celestial imagery in this verse, it could have become "seven stars in the sky."

Verse 8 is the Beatitudes of the Sermon on the Mount, which could have become "April Rainers" by way of the Book of Isaiah, ch.45, verse 8, "You heavens above, rain down righteousness; let the clouds shower it down. Let the earth open wide, let salvation spring up, let righteousness grow with it; I, the LORD, have created it (NIV translation)." This passage appears in the medieval "Liber Usualis" the main source of gregorian chant in monastic services, also well-known to the medieval scholastics, and to scholars of the Renaissance. See William Dunbar's 16th century poem of the same name: "Rorate Coeli Desuper."

Similarly, Verse 9 refers to the nine Muses of ancient Greece, also by way of Christian scholastics: Calliope (epic song), Clio (history), Euterpe (lyric song), Thalia (comedy) Melpomene (tragedy), Terpsichore (dancing), Erato (erotic poetry), Polymnia (sacred songs) and Urania (astronomy). The "nine bright shiners" probably came from the reference to the sun, moon and seven planets known in the 17th century, referred to in this verse.

Verse eleven refers to St. Ursula and the eleven thousand virgins. There are several credible origins for this legend: one is an inscription to two women: "Ursula et Undecimilla, virgines" misread by later readers. Another is that there were Ursula and eleven virgin martyrs, the "MM" being read later on as thousands.

Verse twelve refers to the twelve apostles and the twelve articles of the creed. The song as a whole refers to the twelve days of Christmas.