Bewailing the dead a widespread custom

Irish writer Elaine Crowley (1927-2011) wrote well-rounded stories with involved plots and wonderful characterization. As well, she carried us back into Ireland’s tumultuous history.
In Dreams of Other Days, we meet patriot Daniel O’Connell (1775-1847) as he struggles for Ireland’s independence. And we endure the Great Potato Famine of 1845-49. Thousands died in this famine, so we also encounter the Irish wake.
The following excerpt concerns one of those wakes:  “Then the keeners arrived, tall thin women shrouded in mourning, resembling gaunt black birds. They set up their keen, a thin high wail of desolation, an ear-piercing protest against man’s mortality.”
Keeners are hired mourners, usually paid with whisky and food. Keen is from Irish Gaelic caoine/caonim (wail; to wail). In English since 1850, the noun  keen is defined as, “Irish funeral wail.” The verb, to keen, is earlier — 1811. It means, “to utter the keen for the dead; to wail bitterly.”
Although this kind of display is often associated with Ireland and parts of Scotland, loud lamentation for the dead isn’t unique to Gaels and Celts. Middle-Eastern and Eastern European people also demonstrate grief this way, for example in Russia, Lebanon and Israel. This same custom was known to the Greeks and Romans. Lamentations for the dead are mentioned often in the Bible.
A lamentation is, “a passionate expression of grief.” To lament is to bewail; to mourn passionately. Those laments pipers play are really funeral dirges.
Loudly lamenting the dead is traditional in so many cultures, it’s odd we so seldom hear this kind of mourning in Canada.
Another Irish word meaning keen is ullaloo, which apparently is rooted in the Latin ululatus/ululo (howling; wailing; yelling; to howl to; to resound with howling).
In other parts of the English-speaking world, forms of to keen are often used, albeit not in reference to funerals and wakes. We sometimes hear or use keen/keening simply to describe wailing.
In still other usage, keen is a synonym for “sharp,” or, “intense,” or “piercing.” Thus, we speak of a keen wind or a keen mind. Keen can also mean “eager.” And  in slang usage, a keener is a “hard bargainer; a cheat; a card sharp.” To be keen on means, “interested in — especially in pursuit of love.” 
In these uses, the word isn’t related to the sound of wailing. Nor is it of Gaelic origin. Keen (piercing) is from the Old English cene, which comes from the Old Teutonic konjo (wise; learned). 
Interestingly, Crowley does use keening when describing the wind, but she doesn’t use it in the sense of “sharp” or “piercing.” Still connecting the word to lamenting the dead, she writes, “Sometimes a wind rose shrieking like keening women.”
The surnames, Keene and Keenan, do not appear to be related to the idea of lamentation or paid mourners although the Dictionary of Surnames suggests that both names are Irish in origin. Name dictionaries give such varied meanings as “ancient,” “distant,” “hunter,” and “brave” for these two names.