Spotify Sleep Playlists Include Some Surprisingly Upbeat Music


For some people, falling asleep is easy. For others, it’s a constant struggle and a search for the perfect bedtime routine to help them nod off to dreamland. Chamomile tea, exercise, melatonin, no digital devices after dinner, sleep masks, ear plugs – they’ll try anything. That includes sleep playlists, carefully curated by someone who assures you that this music is the key to final dozing off. But what makes for good sleep music? A new study analyzed hundreds of Spotify sleep playlists to find the musical equivalent of the Sandman.

Researchers from Aarhus University & The Royal Academy of Music in Denmark searched Spotify for playlists that people created to fall asleep to. They collected almost a thousand playlists, each with over a hundred subscribers, to find out if there is a particular type of music that people listen to when they’re trying to fall asleep.

Altogether, these playlists included over two hundred thousand tracks. As you might expect from sleep playlists, many of these were instrumental tracks, slow music, and not very loud. The biggest category the researchers identified was “ambient music”. But there were a few other categories of music as well, with some surprisingly louder or faster-paced tracks such as “Dynamite” by BTS and “Lovely” by Billie Eilish and Khalid.

This is not the first study to attempt to find out what music makes us fall asleep, and also not the first time that the results have been a bit unexpected.

Several studies have found that listening to music before bed could make it easier to sleep, but the music people prefer to listen to is not always the best for a restful night. For example, according to a 2021 study from Baylor University, people can wake up at night from having a song stuck in their head, so it’s not a good idea to listen to catchy tunes before bed. But of course people still did that. Sleep researcher Michael Scullin, who led the earworm study, told Baylor University that “almost everyone thought music improves their sleep, but we found those who listened to more music slept worse.”

Perhaps that also means that Spotify sleep playlists don’t actually include music that’s good for sleeping. After all, if people can’t accurately judge which music will help them sleep, nothing is stopping them from putting a catchy song on a sleep playlist or subscribing to a playlist with a few more upbeat tunes on it.

The new study from Denmark could only see which playlists people subscribed to – not how well the listeners actually slept. But in their research paper, the researchers suggest that there could be a reason for listening to faster and louder music before bed. “One could argue that music with high Energy and Danceability would be counterproductive for relaxation and sleep,” they write, “however it is possible that they could increase relaxation when considering the interplay between repeated exposure, familiarity and predictive processing.” In other words, people might just want to hear their favorite music to end the day.

So we still don’t know exactly which music is actually good for sleeping, but this study at least narrowed down what people choose to listen to before bed. And in the future that could help other researchers figure out what aspects of music actually make you fall asleep and stay asleep.

How a Marine Biologist Remixed Whalesong


In 1971, in the journal Science, two scientists, Roger S. Payne and Scott McVay, published a paper titled “Songs of Humpback Whales.” They began by noting how “during the quiet age of sail, under conditions of exceptional calm and proximity, whalers were occasionally able to hear the sounds of whales transmitted faintly through a wooden hull.” In the modern era, we could listen in new ways: Payne and McVay worked with underwater recordings of humpback-whale vocalizations from a naval researcher who, as the story goes, was listening for Soviet submarines off Bermuda. They analyzed the recordings, and Payne’s own, and found structure and repetition in the sounds, documenting a sonic hierarchy: units, phrases, and themes, which combined into what they called song.

They chose the term advisedly, drawing, they said, on a 1963 book titled “Acoustic Behavior of Animals,” which identified a song as “a series of notes, generally of more than one type, uttered in succession and so related as to form a recognizable sequence or pattern in time.” And there was an intuitive sense in which the whales’ vocalizations sounded songlike. The previous year, Payne had published an album of whale recordings called “Songs of the Humpback Whale”; it sold more than a hundred thousand copies, and became a soundtrack for the conservation movement. Artists, including Kate Bush, Judy Collins, and the cast of “The Partridge Family,” integrated whalesong into their work; in 1970, the composer Alan Hovhaness combined whale and orchestra for a piece called “And God Created Great Whales.” In 2014, a group of ambient composers and artists released a compilation album called “POD TUNE.” Whales’ otherworldly emissions are now literally otherworldly: in 1977, NASA included whalesong recordings on records it attached to its Voyager spacecraft.

Sara Niksic, a biologist and musician from Croatia, is a recent participant in the genre. In 2019, she self-released an album of electronic music titled “Canticum Megapterae – Song of the Humpback Whale.” (Humpback whales belong to the genus Megaptera.) The album contains a track she produced, alongside songs by seven other artists, and combines psychedelic trance and ambient tones—the building blocks of a genre called psybient—with whalesong. Niksic’s record evokes nineteen-nineties classics such as “The Orb’s Adventures Beyond the Ultraworld”; its synthesized clicks, sweeps, and throbs would sound good in the chill-out room at a rave. But the whales add another dimension. Integrated into the tracks, the vocalizations sound at times soothing or playful, and occasionally experimental—sound for sound’s sake. Listening, you wonder about the minds behind them.

Earlier this year, Niksic released “Canticum Megapterae II – The Evolution,” a remix album on which a new group of electronic musicians interprets the track she made for the first volume. The new album, she told me, connects to her own research, which focusses on how whale songs shift from year to year. “Basically, whales remix each other’s songs,” she said. “So I thought this concept of remixes in our music would be perfect to communicate this research about the evolution of whalesong.”

Niksic was born in Split, Croatia, on the country’s coast, across the Adriatic Sea from Italy. She could see the water from her window, and learned to swim before she could walk. “I was always curious about the ocean and all the creatures living down there,” she told me. “The more I learned about animal behavior, the more I got interested in marine mammals, because there is social learning, vocal communication, and culture.” She earned a bachelor’s degree in biology and a master’s degree in marine biology at the University of Zagreb, and went on to work with groups that study whales and dolphins in Australia, New Zealand, and elsewhere; eventually she returned to Split to work at the Mediterranean Institute for Life Sciences, as part of a team called ARTScience, finding ways to creatively communicate the institute’s research.

Humpback whales seem to produce sound largely with their vocal folds. Songs typically range in length from ten minutes to half an hour. All humpbacks make vocalizations, but only males sing; the songs are most commonly thought to act as mating displays, possibly like the bowers constructed by male bowerbirds or the dances performed by male peacock jumping spiders. Maybe, among humpbacks, “the best singer gets the ladies,” Niksic told me. Songs evolve over time, and differ across populations. This slow evolution can be occasionally interrupted by a kind of revolution, in which one population completely adopts the songs of another in a period of just a couple of years or less. “It’s like a new hit song,” Niksic said—a wide and rapid spread of creative content that’s “unparalleled in the animal kingdom, excepting humans.” She went on, “There’s so many similarities between their culture and ours.”

Niksic started working at music festivals after graduate school. When she wasn’t in the field, she was bartending and building stages. She grew curious about producing her own electronic music. As a kid, she’d studied piano and music theory, but she didn’t know how to use software and synthesizers. After spending some time in 2016 helping to map the Great Pacific Garbage Patch, she took courses on electronic-music production. “Most of the time, I was dealing with sound, whether through bioacoustics or music festivals,” she recalled. “So then I thought, I want to try to combine these two things.”

At first, Niksic planned to produce the entire album herself. This proved too ambitious a goal, so she enlisted musicians she’d met on the festival circuit, sending them a high-quality, twenty-minute whalesong recording that she’d analyzed for her master’s thesis. (Her adviser had gathered the recording in the Caribbean.) When Niksic put “Canticum Megapterae” online, under the stage name Inner Child, it quickly earned recognition from both music and science communities. Readers of the Web site psybient.org—a “daily source of chillout, psychill, psybient, ambient, psydub, dub, psystep, downtempo, world, ethnic, idm, meditative and other mind expanding music and events”—voted it compilation of the year. She won an Innovation Award from the University of St. Andrews, in Scotland, spoke at the World Marine Mammal Science Conference, in Barcelona, and appeared at the Boom Festival, in Portugal. Her own track, “Theme 7,” built a downtempo pattern around a long excerpt from the whale recording. Weaving around the snares, kicks, and low, grinding bass line, the whale sounds mournful, almost plaintive, and never strays far from the center of attention.

I asked Niksic if she thinks about what a whale might be thinking when she listens to or composes with whalesong. “That’s a tricky one,” she said. “Who knows what the whale might be thinking? I’m focussing on sound. Their songs are really so musical. And the frequency range they use is crazy. And the richness of the sounds—it’s so intense. And it’s immersive—when I listen to it, I kind of transport into the ocean.”

For the new remix album, Niksic sent “Theme 7” to different artists. One was particularly determined to accurately represent the whale songs. “He didn’t want any whales to think, What the hell is? What the hell did he do with our song?” Niksic said. Perhaps making an electronic whalesong album would be a kind of interspecies cultural appropriation. She was thrilled when Electrypnose, one of her favorite musicians, remixed her track; when she played the remix for the first time, it was “just the most magical night ever,” Niksic said. She was lying on her terrace by the sea, listening to the song, when dolphins swam near. “I’m not kidding you—I think they heard it,” she said. “They were hanging there for the entire night. I didn’t go to sleep. There was a full moon. I was staring at the sky, listening to dolphins breathing, and to this remix, and whales. So even, like, dolphins loved it, not only humans.”

Making the albums has increased Niksic’s own curiosity about whalesong. “I started thinking of more and more questions,” she told me. “I probably wouldn’t think of all of them if I were only doing research.” Are there more innovative or creative whales, just as there are more innovative or creative humans? Are some whales eager to introduce changes into the songs they learn, whereas others happily stick with the originals? (“In our own culture, some artists are pioneers of new musical genres, and then others follow them,” she noted.) Do whales collaborate creatively? Does age play a role in innovation?

Whale songs have become a familiar part of our own culture. But there’s still much that’s mysterious about them, including what drives change and imitation, and how various features influence potential mates and competitors. “There’s a whole other world below the waves that we don’t know anything about,” Niksic said. “There are other cultures that are much more ancient than our human culture. Whales were here long before humans, and they were singing long before we came. I think they are way more developed than us in some ways.” The music on her albums teaches us, among other things, just how much we have to learn.