Song Of The Day

Hopkins' atmospheric "Insides" lumbers with a beat that's 50 stories tall; each gruff bass note hits like a defibrillator to the brain, with subtle glitches providing aftershocks. The music breathes erratically as the rhythmic stomps start to thrash. An astral chorus reaches for the heavens, but everything sputters to a halt, leaving a single note to whisper in solitude.

"Imagine what is possible if you could separate time," the two sing at the outset of "Long Way to Go." They provide a glimmer of what they have in mind during their live performances, wherein Finn samples himself playing one instrument before hopping over to the next, folding moments over on themselves until he's created a temporal loop of multiple Finns existing in one fragmented moment.

There's just something about Iggy Pop. It's that voice: implacable, tomblike, capable of conferring gravity upon the slightest slip of a song. In this case, the song is the cheery ode to misanthropy "I Hate People," by 22-year-old Jemina Pearl, former frontwoman of the short-lived, much-loved Be Your Own Pet.

Sure, "Single Ladies" actually came out in 2008. But since we don't have numbers on this year yet, it's fair to argue that it's the jam of 2009. (Though, admittedly, some would argue that it's neck and neck with Miley Cyrus' "Party In The U.S.A.")

In "Teardrops on My Guitar," Swift tells a common story. She likes this guy named Drew; he likes another girl; she fakes "a smile so he won't see" how much she hurts. Simple enough, but what differentiates Swift from other teen pop stars is that her songs impart viscerally what it feels like to be a teenager, when hyper-real emotions can still be conveyed with timidity.

All alien-science synthesizers, crispy hi-hats and galvanizing delivery, "Umbrella" is what happens when an unclassifiable singer meets an ineffable song. It turned out to be the summer jam of 2007, echoing across the world to an indelible refrain: "ella, ella / ay, ay, ay."

When it was announced that Goodie Mob's Cee-Lo Green and producer Danger Mouse were going to collaborate as Gnarls Barkley, there was no predicting the massive success of "Crazy." It was a song everyone seemed to like, and it remains a left-field wonder of psychedelic soul.

In the dynamite 2005 single "Since U Been Gone," Clarkson belts out one of the decade's great pop songs, following a familiar formula — jilted ex-girlfriend indignantly declares independence — but infusing it with energy, charisma and full-throated intensity. Sure, the over-the-top, loud-louder-loudest production helps. But it's an unmistakably great pop-rock song, thanks most of all to an unmistakably great pop-rock singer.

A product of the post-teen-pop, pre-Kevin Federline Britney Spears of early 2004, "Toxic" was the second single from Spears' fourth studio album, In the Zone. No longer apologetic or defensive for breaking away from her '90s virginal teeny-bopper image and sound, the Spears in "Toxic" is out to have a good time on her own terms.

"In Da Club" was a ubiquitous presence on seemingly every commercial radio station, at every hour of the day. The song made 50 Cent out to be a loveable, huggable roughneck the likes of which the ladies hadn't seen since Method Man. "I'm into having sex, I ain't into making love," he drawls, adding, "So come give me a hug."

Mainstream rock was in dire straits in the early 2000s, but out of a world of jaw-wired-shut self-plagiarizers and rap-rockers came arguably the power-pop anthem of the decade. Jimmy Eat World's "The Middle" is a hopeful, energetically poppy punk song about being yourself.

As the music industry began to break apart and go niche, it's remarkable that a group as artistically ambitious as OutKast could break through the way it did. But Stankonia was one of those game-changing records that made everyone perk up and pay attention.

Every weekday from Nov. 9 to Nov. 20, Song of the Day will survey the past decade, one year (and one song) at a time, with an emphasis on America's most popular music. For the year 2000, it's 'N Sync's "Bye Bye Bye," which feels like the product of a shadowy pre-Sept. 11 world in which telegenic boys dance in unison.

In Visqueen's crunchy, urgent power-pop song "Hand Me Down," crunchy guitars and Rachel Flotard's incomparable voice simultaneously destroy and mesmerize. As its title suggests, "Hand Me Down" is rooted in a singular bond that spans generations.

At first, The xx's "Crystalised" resembles an undercooked demo, as singer-guitarist Romy Croft and guitarist Baria Qureshi strum gloomy notes over muted, rumbling drums. But then the group glides into the chorus and the sudden shift to a bright, melodic key feels jarring in the best sense possible. It's like looking at one of those Magic Eye paintings: Suddenly, everything comes into focus.