In 2016, I've had to abandon my long-held, entirely nonscientific theory about the timing of the deaths of much-loved musicians.

It's not the they-come-in-threes theory, which, if true, might provide solace in a year when David Bowie, Merle Haggard, and Prince have been lost. If that numerological reasoning holds true, maybe there won't be any more enormously influential titans exiting for a while.

No, my theory was calendrical. They die in December, it always seemed to me.

That idea is partly based on the memory of the most shocking rock death - John Lennon's assassination in December 1980 - as well as a long list of others who left as days grew short. For starters: Joe Strummer, Kirsty MacColl, Curtis Mayfield, Captain Beefheart, Ian McLagan, Odetta, Roy Orbison, Frank Zappa, Ike Turner and Teena Marie. None would "make it through December," to paraphrase a great Haggard song.

The sense that bad things are about to happen around the holidays haunts me partly because my father died in December 1990. And I can't help but remember writing James Brown's obituary on Christmas 2006. As one of my favorite '70s English rock bands, Mott the Hoople, whose drummer, Dale "Buffin" Griffin, died in January, put it: "Death May Be Your Santa Claus."

But with all due respect to Stone Temple Pilots singer Scott Weiland, Motorhead's Lemmy Kilmister, and R&B vocalist Natalie Cole, all of whom died in the last month of last year, 2016 has made that death toll seem minimal.

Since Jan. 1, music fans have felt like they were being pummeled with the one-after-another loss of heroes who played crucial roles in pop history and their emotional lives. Never mind Kanye and Drake: The biggest music stories of 2016 haven't been new albums, they've been the deaths of people who made great old ones.

It all started with Bowie, the pansexual '70s glam and '80s pop innovator. The first spectacular rock death of 2016 capped a dramatic final act in which he kept the severity of his illness secret and released one final album days before his passing.

It also provided the global grieving template we're going through with Prince. Online, there's a rush to RIP and self-publish your grief. There are cruel celebrity death hoaxes, and crossed-fingers hope that the bad news can't possibly be true, can it? It also means musicians get killed repeatedly online. I can't tell you how many times Richie Havens, who died in 2013, has been pronounced dead on my Facebook feed.

But when the awful news turns out to be true, digital media means we know much, much more about newly deceased stars a week after their death than we did while they were alive.

With Bowie, there was a lifetime's worth of visually arresting performance content to be reassessed or seen for the first time. The same has happened with Prince, though it's been trickier, because he was so protective of his music.

Fans have had to dig deeper to tell personal stories of his eccentricities and to exhume footage. Have you checked out bootleg clips of Prince tearing up the Rolling Stones' "Honky Tonk Women" or Led Zeppelin's "Whole Lotta Love"? How about Jimmy Fallon's recounting the Purple One's challenging him to a ping-pong showdown? Or his fabulous, first-ever TV performance on The Midnight Special in 1980?

Trust me, they're worth it.

After Bowie's death in January, Glenn Frey of the Eagles, Maurice White of Earth, Wind and Fire, and Paul Kantner of Jefferson Airplane all passed. And lesser-knowns got ignored, like Mic Gillette, the Tower of Power founder, and Signe Anderson, the original Jefferson Airplane lead singer, who died on the same day as Kantner. At the time, a former journo colleague quipped to me: "From now on, you're on the obituary beat."

Sad but true. Since then, Beatles producer George Martin, A Tribe Called Quest rapper Phife Dawg, country singer Joey Feek (of duo Joey + Rory), Prince protégé Vanity, and saloon-singer scion Frank Sinatra Jr. have met their maker. Philadelphia has been hit hard: Gamble and Huff guitarist TJ Tindall (who will be memorialized at Underground Arts on May 22), doo-wop singer (and Questlove's father) Lee Andrews Thompson, and "Me and Mrs. Jones" crooner Billy Paul.

The living are kept busy paying tribute. The cast of Hamilton romped though Prince's "Let's Go Crazy." D'Angelo brought tears with "Sometimes It Snows in April." Beyoncé led a "Purple Rain" sing-along in Miami and did Vanity 6's Prince-penned "Nasty Girl."

As eulogist in chief, Bruce Springsteen has covered Bowie's "Rebel Rebel," the Eagles' "Take It Easy," and Prince's "Purple Rain."

"There's never been anyone better," he said of Prince last weekend in Brooklyn.

This year is stacking up to be the saddest year in pop music history since Janis Joplin and Jimi Hendrix, both 27, died within a month of each other in 1970. After Paul passed last weekend - within days of Prince, blues-rock axman Lonnie Mack, and Congolese bandleader Papa Wemba - Bootsy Collins tweeted: "Losing our greats so quick it's hard to keep up." And St. Vincent, a.k.a. Annie Clark, responded to Prince's death with a call to action: "The world seems to be purging itself of geniuses. Creators, let's get out there and [expletive] create."

What's behind the wave of pop-star deaths? We don't know yet what killed Prince, but there's not a confirmed drug or alcohol or vehicle crash among the fatalities listed above. The only ones still in their 40s, in fact, were Phife, "the Funky Diabetic" who suffered from kidney disease, and Feek, claimed by cancer.

It's mostly down to the passage of time. As Prince put it in "1999": "Life is just a party / And parties weren't meant to last." ("If I gotta die, I'm going 2 listen to my body tonight" is the corollary.) Elvis Presley's "Heartbreak Hotel" came out in 1956, so the youth-culture pop-music world as we know it is now 60 years old. The clock is ticking on a whole lot of people whose music has shaped people's identities for decades.

The flip side is all the geezers who are still alive and rocking. See the perennial 2012 Onion headline: "Keith Richards' Housekeeper Has Braced Herself For Finding Dead Body Every Morning Since 1976."

The Los Angeles Times reports that an event I'm calling the Methuselah Festival is planned for the California desert this fall to bring together the Rolling Stones, Paul McCartney (who plays Citizens Bank Park on July 12), Bob Dylan (at the Mann Center the next night), the Who, Neil Young, and Pink Floyd's Roger Waters.

Those guys are really old - with a front man average age of 72. But that's young compared to the originators - Chuck Berry, Fats Domino, Jerry Lee Lewis, and Little Richard - whose faces appeared in a meme last week with the words: "These giants still roam the earth."

They do, and the idea is that we should appreciate them now. Hear, hear - I couldn't agree more. I don't see it happening collectively, however, until they've passed. Nothing unites us like death, and now social media.

What's that line by Joni Mitchell - a Prince fave, by the way, check out his cover of "A Case of You" - about not knowing what you got till it's gone? When our favorite pop stars die, we're reminded of our own mortality, and how their music has worked its way into our souls. When they leave us, we lose a part of ourselves.