I like how NO ONE said a damn thing about the similarities in the two melodies, but the tacked-on apostrophe mechanics poll generated plenty of comments.

OK. Let me say right away that despite what I am about to say, IF YOU PICKED THE FIRST ANSWER (Vaughan Williams') I DO NOT NECESSARILY THINK YOU ARE WRONG. Or a bad person. Or scorn-worthy. In fact, it was the choice of professional writers and editors as well most of the non-pro people on my friends list whose writing I respect. I certainly do not hold myself up as an exemplar of the English language, and I'm obviously not a professional writer or editor ... just a nit-picker.

Now then. When I was making the entry, I initially wrote "Ralph Vaughan Williams's Fantasia on Greensleeves," which I do personally believe to be more correct, as do a few of the more linguistically-minded of you. However, it is becoming clearer and clearer that the alternative is, if not the dominant usage, at least appreciably common. And I knew that my choice would look awkward to some people, so I avoided it altogether and made a poll to confirm my suspicions.

A little research pointed me to what I now believe is the source of the shifting tide: the Associated Press stylebook. After consulting a dozen reference manuals, it became apparent that there is a great deal of confusion — and in fact outright dissent — among "authorities" when it comes to forming possessives of singular nouns ending in s. This, from the Oxford Dictionary of American Usage and Style, is fairly representative of the official prescription, and singles out the AP as a rogue.

Singular Possessives.

To form a singular possessive, add -'s to most singular nouns—even those ending in -s and -x (hence witness's, Vitex's, Jones's, Nichols's). E.g.: “Noting Congress's move to regulate maternity hospitalization, managedcare advocates predict that politicians would legislate health care” (U.S. News & World Rep.). Although the AP Stylebook (6th ed. 1996) calls for nothing more than an apostrophe if the word already ends in -s (p. 163), most authorities who aren't journalists demand the final -s as well (i.e., Bill Forbis's farm, not Bill Forbis' farm). See William Strunk, Jr. & E. B. White, The Elements of Style 1 (3d ed. 1979).

There are three exceptions to this rule. The first is the standard one: Biblical and Classical names ending in -s take only an apostrophe, hence Jesus' suffering, Moses' discovery, Aristophanes' plays, Grotius' writings. (No extra syllable is added in sounding the possessive form.) The second exception is for words formed from a plural. Thus General Motors should make General Motors', not General Motors's—e.g.: “A merger by General Motors will excite great interest in an enforcement agency simply because of General Motors's [read General Motors'] size” (E. W. Kintner, An Antitrust Primer, 1973). The third exception (a minor point) is discussed at (J).^†

Plural Possessives.

For most plural possessives, use the ordinary plural form and add an apostrophe to the final -s: Smiths', Joneses', bosses', octopuses'. The one exception is for plurals not ending in -s, for which -'s is added as in the singular possessive: brethren's, children's, men's, women's.

Writers sometimes confound the singular and plural possessives, most commonly by misusing the singular for the plural—e.g.: “I don't much admire the Wales's [read Waleses'] taste in expensive schools” (Guardian). (The reference was to the Prince and Princess of Wales.)/ “According to the lawsuit, on the day before he died, a classmate walked into the boy's bathroom [read boys' bathroom (because it's a school bathroom)] and interrupted Shawn before he could hang himself with a shirt” (Austin American-Statesman).

— "possessives" The Oxford Dictionary of American Usage and Style. Bryan A. Garner. Oxford University Press, 2000. Oxford Reference Online. Oxford University Press. Accessed 13 January 2006. http://www.oxfordreference.com/views/ENTRY.html?subview=Main&entry=t26.e1727&category=

Of course, the "Vaughan Williamses" question was plural, not possessive, so since we never use apostrophes to form plurals, "Vaughan Williamses" is the only acceptable answer. Sorry, that was kind of a trick question. I don't even remember who said what for that one, so don't worry if you got it wrong.

I actually found a grammar forum online that deals specifically with the surname Williams, but the answer, while good, only adds to the confusion.

The vast majority of the reference works I consulted agree with my Vaughan Williams's, but I think it ultimately will come down to pronunciation and a subjective call on what "sounds awkward."

CHW, J'y, H_R, PoP, FMF ... we are fighting a losing battle, I'm afraid.

† † † † †

^†J.  Attributive Nouns Ending in -ed. Words ending in -ed become awkward as possessives. This happens primarily in law. With such phrases as the insured's death or the deceased's residence, it's better to use an of-phrase—hence the death of the insured and the residence of the deceased. (Or you might try the decedent's residence).