Sia performing at South by Southwest in 2008. (Photo: Wikimedia Commons)

The No. 1 song in America—the weekly winner of the top slot on the Billboard Hot 100—defines a period. It blares out of stores and homes, and offers us a glimpse into the zeitgeist. Yet since the 2016 election, every single No. 1 song has been sung by a man. It's now been 51 weeks since The Chainsmokers' "Closer" took the No. 1 spot from Sia's "Cheap Thrills" on September 3rd, 2016. Though the mantle has been passed a few times since, not once has the top spot gone to a woman. This marks the longest stretch the No. 1 spot has gone without a female artist since the chart's invention in 1958.

Up until the election, 2016 had been pretty good for women in popular music, and the No. 1 spot on the Billboard Hot 100 had been incredibly diverse. The year opened with Adele's "Hello," and cycled through nine other No. 1 hits before the presidential election. Three of those 10 No. 1 songs were performed by women (along with "Hello," Rihanna's "Work," and Sia's "Cheap Thrills") holding the spot for 16 of the 45 weeks. In addition to decent gender diversity, non-white performers held the top slot for 22 of those 45 weeks. It wasn't until November 9th, the day after the 2016 presidential election, when "Closer" took the top spot, that the complete shutout of women began.

The first hit song of the Trump era, "Closer," was made by two white men who once released a sexist single called "#Selfie" (and once made complete fools of themselves on American Idol). The Chainsmokers No. 1 reign with "Closer"—which lasted 12 consecutive weeks, and tied Leann Rimes' record of 32 weeks in the top 10—felt appropriate for the political climate last November; a baffling and homogenous close to an otherwise diverse and vibrant year in music. No female artist has held the top spot on the Billboard Hot 100 since Donald Trump was elected president—a male-dominated streak that hasn't happened since the presidency of Dwight D. Eisenhower.

Since the election, nine songs have held the No. 1 slot: The Chainsmoker's "Closer," Rae Sremmurd's "Black Beatles," The Weeknd's "Starboy," Migos' "Bad and Boujee," Ed Sheeran's "Shape of You," Kendrick Lamar's "Humble," Bruno Mars' "That's What I Like," DJ Khaled's "I'm the One," and Luis Fonsi's "Despacito." Since 2000, the Billboard Hot 100 has averaged roughly 12 individual No. 1 hits per year, meaning this year's pace of turnover is consistent with the average. What's abnormal this year is that none of those hits have been by women.

Popular music has always struggled with gender equality. The Top 40 songs on the Billboard Hot 100—for example—has averaged around 30 percent female performers in each of the last three years. That matters because a large fanbase can sneak an artist into the Hot 100 songs, but a song has to really stick to make it into the Top 40. The Billboard Hot 100 calculates purchases, streams, and radio plays into its charting algorithm, and in all of those categories male performers are getting more play time than women—even in a year when Beyoncé and Rihanna put out albums.

No female artist has held the top spot on the Billboard Hot 100 since Donald Trump was elected president.

According to Billboard's own data, 49 percent of the Billboard Hot 100 No. 1 hits in the 1990s were performed by women. That share dropped to 40 percent through the 2000s before climbing back up to an average 46 percent of the 2010s, up through March 2017. But the aggregate percentages don't account for the most recent dips. In a piece written for Vulture last year, I found that only 22.3 percent of songs in the Top 40 were performed by women in 2016—a marked difference from the decade average of 46 percent. Somewhat similarly, only 30 percent of the weeks in 2016 had a woman sitting on the top of the chart. Even with those rapidly dwindling metrics, 2017's continuation of the Billboard Top 100's shutout of female chart toppers—now going on 51 weeks—represents a stunning decline.

It's not uncommon for a male-led song to hold the top spot into the 20-week mark. On average, there's a stretch of 20 or more straight weeks of male No. 1 hits roughly every three years. This is usually attributed to a smash hit that stays on top of the chart for a long time, such as Bruno Mars' 2015 hit, "Uptown Funk" at 15 weeks, or 2004's "Yeah!" by Usher, which lasted 12 weeks. But the rate of male-dominated streaks at the top of the chart had been dwindling over the past few decades. This year, it's Fonsi's "Despacito" featuring Justin Bieber and Yankee Daddy, which has held the crown for 13 weeks and counting.

But even with the "Despacito" reign, a 51-week stretch of all male performers is almost unprecedented. To find a stretch of more than 30 weeks in a row, we have to go all the way back to 1988. There were six stretches of more than 30 weeks without a woman at No. 1 throughout the 1970s and '80s. To locate a male-dominated top-slot streak of 40-plus weeks, we have to go all the way back to 1968.

Not since Lyndon Baines Johnson's presidency and the Vietnam War have we gone even close to this long without a woman in the No. 1 slot. The only other time the No. 1 spot has been more dominated by men in the history of the Billboard Hot 100 chart was at its inception. Starting with the chart's debut on August 4th, 1958, there was a 97-week stretch before a woman broke the chart glass ceiling on June 27th, 1960: Connie Francis with "Everybody's Somebody's Fool."

Some of this, of course, can be attributed to happenstance. Between Sheeran's 11-week dominance with "Shape of You" and Fonsi's ongoing reign with "Despacito"—both global hits that have captured large international audiences—there hasn't been much room for a female artist to top the charts. But this is more than just a couple of smash hits elbowing out female artists. Currently, there are no songs in the Top 10 by female artists. The highest ranking song by a woman comes is Julia Michaels' "Issues," coming in at No. 15. There hasn't been a woman with a song in the Top 10 since Miley Cyrus' "Malibu." Though "I Don't Wanna Live Forever," which features vocals from Taylor Swift, peaked at No. 2 in March, that song was listed as a collaboration, with Zayn. The closest a female performer alone has come to the No. 1 spot is Katy Perry's "Chained to the Rhythm," which debuted at No. 4 in March and then immediately tumbled down the chart.

Even without new albums from big artists such as Beyonce, Rihanna, and Swift, the lack of female presence atop the chart has been alarming. Perry has nine No. 1 singles, but none this year. Cyrus took the No. 1 with "Wrecking Ball" in 2013, but barely scratched the Top 10 this year. Yet neither have reached there this year. There are only five songs in the Top 40 by women—a paltry 12.5 percent. This year's only hope, it seems, is a surprise release from Swift.

A No. 1 hit is always a bit of its own unquantifiable sorcery. It's achieved by a combination of radio plays, streams, purchased albums, and dumb luck. There's also no cash bonus for a No. 1 hit. The only thing it offers, really, is bragging rights. It's the chance to dominate the airwaves, to know that you control the conversation in America, that your work will blast out of car windows for weeks relentlessly. But women haven't had that kind of win this year in music.

This year, thus far at least, is a year that consistently and unrelentingly bucks at culture made for or by female creators. Sure, the No. 1 spot could just be in an anomaly year—it would be the longest anomaly in almost 60 years—but it's taking place in the context of a broader reversal in appreciation for women's work occurring all over American culture. Female musicians are spoken about less in the context of their work, and more in the potential machinations of their "feuds." It took public outrage, much from the show's own star, for X-Files producers to hire female writers and directors. Wonder Woman was a massive box-office success, but had to survive boycotts and sexist backlash. There may not have been demonstrative protests of female musicians this year, or outright hatred. But the constant, quiet pushing away of their work feels like a silent dismissal of female musicians as irrelevant or unimportant in a year where they should be anything but.

Trump's election may not have directly resulted in the Hot 100 female shut-out. But this overt rejection of female-created culture in the post-election era, the type of gender segregation that did not exist—at least not so glaringly—in 2016, seems to directly parallel the type of misogyny that's become more overt, and with each passing week of the Billboard charts, seemingly more OK.