Radiohead have always had a special gift for making glitchy sad bastard music sound warm, inviting, and irresistibly catchy. But no matter how much you love to dance to "Idioteque" or rock out to "2+2=5," Radiohead's speciality, as far as most are concerned, lies in their ability to mine the depths of melancholy and find emotional resonance. (Or maybe I'm just a huge fanboy and it's really just one-dimensional music for moody people, shut up you're not my mom.)
Nevertheless! If we can accept the premise that Radiohead specialize in turning depression into aural pleasure, the question remains: which song is the most depressing Radiohead song? Thankfully, data scientist and Radiohead-head Charlie Thompson decided to find out using only the most scientific methods available.
You can read all about his project in tremendous detail on his site here. The basics are: he used Spotify to measure a song's valence (a measure from 0.0 to 1.0 describing the musical positiveness conveyed by a track, with high valence meaning joy and low meaning sadness), then used Genius and other programs to pull apart how sad the lyrics are, which he then turned into an overall "gloom index."
You can peruse the gloom index (aka "Data Driven Depression") here, but the winner was the closing track of their last album, the long-awaited "True Love Waits"! It was followed closely by the likes of "Motion Picture Soundtrack," "Give Up The Ghost," "High and Dry," "Let Down," "Exit Music," "Pyramid Song," "Dollars and Cents," "We Suck Young Blood," "Videotape" and "Tinker Tailer Soldier Sailor Rich Man Poor Man Beggar Man Thief." He writes of the conclusions:
Of all nine studio albums, Radiohead’s latest release, “A Moon Shaped Pool,” boasts the lowest average gloom index. This is driven largely by the fact that its finale, “True Love Waits,” was the gloomiest song overall. It’s also apparent that “A Moon Shaped Pool” broke a trend of relatively less depressing albums since 2003’s “Hail to the Thief.”
In case you were wondering, he found that the "happiest" Radiohead songs are "15 Step," "Feral" (whose lyrics are less words and more fun mouth sounds), "Bodysnatchers," "Jigsaw Falling Into Place," "Go To Sleep," "Pakt Like Sardines In A Crushed Tin Can," and "Airbag." Hey, if singing an ode to surviving a car crash isn't joyous, I don't know what is.