Amy Winehouse’s battles battles with drugs, drink and depression were nightmarishly publicized in a mediascape her forebears never could have imagined. (AP Photo/Matt Dunham)

And then there was the “27” — rock-and-roll’s most dangerous number. It’s the age that took Kurt Cobain, Janis Joplin, Jimi Hendrix, Jim Morrison and now a singer whose battles with drugs, drink and depression were nightmarishly publicized in a mediascape her forebears never could have imagined.

Those forebears make up the “27 Club,” a group of musicians who all died at 27. Ron “Pigpen” McKernan of the Grateful Dead died of a gastrointestinal hemorrhage linked to alcohol abuse. Brian Jones of the Rolling Stones died in his swimming pool. Chris Bell of Big Star died in a car accident. So did D. Boon of the Minutemen. Delta bluesman Robert Johnson died in 1938 under mysterious circumstances — some say he was poisoned while others cite a Faustian deal with the devil. But he was definitely 27.

The eeriness of 27 has spurred decades of theorizing in music circles — enough to inspire Eric Segalstad’s book “The 27s: The Greatest Myth of Rock & Roll.” Is it the age of the psychic slump? The age your body refuses to tolerate your addiction? The age that fate decides to give you a disease, have you murdered or wrap your car around a telephone pole?

We only really know what happens to the 27s after 27: Their swirling mythologies congeal around a relatively small body of work. Many of these artists were young visionaries who left bold marks but didn’t live long enough to slide into mediocrity.

For a singer of her renown, Winehouse’s discography was­­ minuscule. She left us with only two albums (20-some songs in total), and her almost-forgettable 2003 debut, “Frank,” is the sound of a teenager searching for her voice in the gray area between R&B and jazz.

Thankfully, she found it in 2006 with “Back to Black,” an album where her bruised contralto predicted a future both bright and dark. You can hear it in “Rehab,” a smart, self-aware jab at the struggles with substance abuse that she was bound to lose. (Police have not said how Winehouse died; postmortem results will not be released until Monday or Tuesday.)

The success of the song and the album earned Winehouse a record-
setting five Grammys in 2008. And it made her influential. Without her, Cee-Lo never would have recorded his vintage-R&B-plus-four-letter-word megahit, “[Expletive] You.” And this year, British soul chanteuse Adele has dominated the American popscape as if playing Winehouse’s surrogate.

The rest of us played a different kind of imitation game. Since breaking in the States, Winehouse has inspired countless Halloween costumes. (Is there a bigger sign of pop superstardom?) She also inspired countless tattoos, unspooling beehive hairdos and upper-lip piercings. (Okay, maybe these.)

It’s strange to think that she was younger than Britney Spears. Like Robert Johnson seven decades before her, Winehouse sounded wise and wounded beyond her years. And like Cobain, Hendrix and Joplin, Winehouse’s music had a sense of strength and purpose that she — and they — failed to summon in their own lives. On the eve of the U.S. release of “Back to Black” in 2007, Winehouse told The Post, “I think the record speaks louder than any of my stupid actions or things that I say.”

Even if it did, the world chose not to hear it that way. And that’s what sets Winehouse apart from the 27s who came before her. She lived, thrived, struggled and died in the information age, where the digital newsstand’s constant churning pulled her reputation under like so much quicksand.

She would surface constantly in British tabloids and on American celebrity blogs, often bruised up, sometimes barely dressed, occasionally under arrest, once clutching what appeared to be a crack pipe.

The Internet’s fixation with her misdeeds actually captured us at our most revolting. For years, the Web site When will Amy Winehouse die? asked contestants to predict the date of the singer’s death for the chance to win a free iPod. On Sunday afternoon, the site read: “Amy Winehouse has passed away. . . . Winner will be announced later.”

As Winehouse’s life unraveled, the music stopped. And with the metabolism of pop music perpetually increasing, five album-less years felt like a lifetime. When Winehouse stumbled offstage during a botched comeback gig in Belgrade in June, the celebrity blogosphere reflexively gawked. The music world hardly made note of it. Winehouse had been transformed from a once-in-a-generation voice into a tabloid punch line and would never make it back.

That’s the tragic subtext that coursed through Saturday afternoon. The Internet was percolating in mourning, but in Washington, radio playlists hardly budged. Winehouse’s music was nowhere to be heard.

I flipped on Washington’s Hot 99.5 shortly after the news broke, expecting “Rehab” or “You Know I’m No Good” or “Tears Dry on Their Own” to come pouring through the speakers.

Instead, it was the Band Perry’s country-pop hit “If I Die Young.”