by Jennifer Drapkin, Kevin O'Donnell and Ky Henderson

They’re not the most beautiful songs, or the most musically important. In fact, a few could literally drive you nuts. But the following tunes—some as old as Mozart, others as current as Beyonce?—have fundamentally altered the world we live in at some point in the last quarter century. They’ve saved lives, brought glory to America, and gotten teenagers to use deodorant. Somehow, they’ve made a difference. So, ladies and gentlemen, put your hands together for the ultimate power playlist. Let the countdown begin!

Music That Makes Sewage Disappear For all the chatter about how Mozart makes your kids smarter (false!) or how it helps with the SATs (possibly), the one thing that Mozart definitely seems to do is make sludge-eating microbes digest faster. A sewage treatment plant in Treuenbrietzen, Germany, has experimented with different operas, playing them at high volume through loudspeakers set up around the site. "The Magic Flute" seems to work best. Anton Stucki, the plant's chief operator, believes the reverberations quicken the pace for breaking down refuse. "We think the secret is in the vibrations of the music, which penetrate everything—including the water, the sewage, and the cells," he says. "It creates a certain resonance that stimulates the microbes and help them work better." Stucki doesn't even like opera; he's a rock 'n' roll fan. But he tolerates Mozart because it makes the microbes more efficient, saving the plant up to $1,250 a month.

The Drunk-Dialing Song For nearly three decades, this single has been a gift to smashed college kids everywhere. Ever since the song was released in 1982, crank callers have been dialing 867-5309 and asking for “Jenny.” People who are unfortunate enough to be assigned the number can look forward to dozens of prank calls a day, depending on where they live.

A few people have managed to turn the digits to their advantage. In 2004, disc jockey Spencer Potter of Weehawken, N.J., discovered 867-5309 was available in his area code and picked it up, thinking it would be good for business. Almost immediately, Potter was overwhelmed by the volume of calls. So in February 2009, he sold it on eBay to Retro Fitness, a health club that felt the digits fit perfectly with its 1980s-nostalgia theme. In the end, Potter made $186,853.09—a number he could live with.

The Song That Showed Saddam's Softer Side

© INA/Handout/Reuters/Corbis

You might think winning elections is easy for dictators—after all, they aren’t running against anyone. But there’s still pageantry involved, which Saddam Hussein took seriously. To win the hearts and minds of Iraqis in 2002, Hussein boldly chose as his campaign anthem an Arabic cover of Whitney Houston’s version of “I Will Always Love You” (written by Dolly Parton). The song was played alongside footage of the dictator kissing babies, shooting guns, and striking heroic poses on Iraq’s three TV stations continuously during the election season. If that’s not proof Hussein tortured his own people, we don’t know what is.

The Tune That Revolutionized the Underarm Industry Kurt Cobain claimed he didn’t know Teen Spirit was a brand of deodorant when he wrote Nirvana’s 1991 grunge anthem. In fact, the name of the song came from his apartment wall, where a friend had spray-painted “Kurt Smells Like Teen Spirit.” But the song’s impact on the antiperspirant was undeniable. The product’s manufacturer, Mennen, came out with a new tagline: “Do you smell like Teen Spirit?” Sales of the deodorant skyrocketed, and Mennen quickly expanded its line of Teen Spirit products; six months after the song was released, Colgate-Palmolive bought the company for $670 million. Though grunge fans didn’t care so much about how they dressed, apparently they cared how they smelled.

The Sound that Ended Silence Forever You may not realize it, but you know this tune all too well. Nokia introduced the 13-note piano phrase 20 years ago, creating the first ringtone. It’s estimated the passage is now heard 1.8 billion times around the world each day, about 20,000 times per second. The ringtone comes from “Gran Vals,” a 1902 guitar solo written by classical guitarist Francisco Tarrega. In 1993 the tune was hijacked by Nokia exec Anssi Vanjoki, who thought it would be the perfect default ring for the sleek, new half-pound Nokia 2110. Today, you’re not the only person tired of the tone. The search for alternate phone sounds has turned ringtones into a multi-billion dollar business.

The Song That Toppled a Dictator Sometimes music moves people. And sometimes it moves them out of hiding. In December 1989, the United States invaded Panama after dictator Manuel Noriega was publicly exposed as a drug czar. Noriega took refuge in the embassy of the Vatican on December 24, and American troops immediately surrounded the compound. To smoke him out without bombing the place, soldiers of the U.S. Southern Command Network Radio turned to Van Halen.

Loudspeakers were set up around the compound and the sonic blasting began. After 10 days of being assaulted by the rock group’s “Panama” and other songs at high decibel levels, Noriega decided that he’d rather be behind bars, and on January 3, 1990, he surrendered. He was convicted on eight counts of drug trafficking, racketeering, and money laundering—all because he couldn’t handle a few power chords. Incidentally, the song isn’t even about the Central American country. Legend has it that it’s about lead singer David Lee Roth’s station wagon.

The Song That Proved Some Children Go Missing for a Reason

Few people pay attention to public service announcements, but back in 1992, lots of people watched music videos on MTV. So on paper, it seemed like a great idea to combine the two. For Soul Asylum’s “Runaway Train,” director Tony Kaye made a video featuring missing children, hoping to find them. And it worked; the video located so many runaways that Kaye made six versions—three for the United States and one each for the United Kingdom, Australia, and Germany.

The problem was, when missing children turn up, the results aren’t always pretty. Some were found dead. Several others were forced to return home to horrible situations. In 2006, Soul Asylum guitarist Dan Murphy reflected on the consequences: “There’s a reason that young kids run away, mostly because of abuse,“ he told the Pasadena Weekly. “There were some happy results from [the video], but you have to resolve the situation that caused an 11- or 13-year-old to think the harsh world is better than their home.”

18. “Gates of Hades” (Nick Ashton)

The Sound of Getting Stoned Sure, music can lift your spirits, but can it actually get you high? Plenty of U.S. teens claimed to be getting seriously buzzed after listening to “Gates of Hades,” a song that purportedly induced feelings in listeners ranging from pleasant dizziness to raging hallucinations. “Gates of Hades” and other tracks like it spawned a craze in 2010 called “i-Dosing.” Developed by Nick Ashton, the technology relies on “binaural beats,” in which a tone of one frequency is played into the right ear and a slightly different frequency is played into the left. Together, the tones supposedly synchronize brain waves, simulating such mental states as getting drunk, falling in love, or sexual arousal.

In 2010, i-Doser.com offered the song for free on YouTube as a sort of gateway drug, then sold additional tracks on their home page. According to Ashton, more than a million people paid for the songs that year alone. Before long, parents and authorities tried to kill the party; one Oklahoma City school went so far as to ban iPods in schools, so students couldn’t get high during homeroom. But it turns out parents didn’t have much to fear—though some teens claim to get buzzed off of i-Dosing, there’s no evidence to suggest it’s addictive or leads to using hard drugs. For the most part, it’s just noise.

The Song That Proved Subliminal Messaging Is Weak Can a song drive you to suicide? In 1990, the heavy metal band Judas Priest was accused of prompting two drunk Reno, Nev., youths to shoot themselves after repeatedly listening to “Better By You, Better Than Me.” (One died instantly; the other survived after blowing half his face off.) Did the lyric “Do it,” allegedly hidden in the song, push them over the edge? Experts testified on both sides, but the judge dismissed the case, ruling, “The scientific research presented does not establish that subliminal stimuli, even if perceived, may precipitate conduct of this magnitude.” The precedent hasn’t been challenged since. As lead singer Rob Halford later noted, he had no reason to ask fans to commit suicide. If anything, he’d issue the command, “Buy more of our records.”

The Song That Gave Pirates Courage Until the End The pirate way to handle a death sentence is simple: booze and Ricky Martin. After being convicted of hijacking a ship and slaughtering its crew, 13 pirates were condemned to death in China in 2000. The morning of their execution, the pirates were given 30 minutes to visit with relatives, eat their last meal, and drink all the rice wine they could stomach. As they were led through the streets of Shanwei, the gang started loudly singing the 1998 World Cup theme—Ricky Martin’s “The Cup of Life.” In their final moments of drunken revelry, the pirates chanted, “Go! Go! Go! allez! allez! allez!”—the song’s refrain— and jumped up and down in their shackles. It was the best reception a Ricky Martin song had been given in years.

The Song That Made Music Safe for the Internet When compact discs were introduced in 1982, consumers marveled at the amount of information they could store. For every three-minute song, a CD uses about 32 megabytes of data. But that size proved to be unwieldy in the early, pokey days of the Internet. Using an old, dial-up modem, it might take eight hours to transfer or download a single song. So in the early 1990s, German engineer Dr. Karlheinz Brandenburg pioneered digital compression techniques for the MP3, crunching the size of audio data by a factor of 11. While tweaking the format, Brandenburg used Suzanne Vega’s 1987 a cappella rendition of “Tom’s Diner” as the benchmark for sonic quality. He reasoned that if he could get her warm vocals to sound good on MP3, then the new platform would work with just about anything. So, if you love downloading music, thank Vega for having such a pretty voice.

The Song That Woke up the Astronauts As the astronauts of Atlantis orbited the Earth during NASA’s final space shuttle mission, they experienced 15 sunrises and sunsets every day. Consequently, their circadian rhythms were thrown off a little. Since a regular alarm clock just wouldn’t cut it, on July 16, 2011, the crew received a special wake-up call from R&B diva Beyonce?. The superstar got the astronauts out of bed with her girl-power anthem “Run the World (Girls).” Then she gave a shout-out to the only woman on the four-person crew, Sandy Magnus: “This song is especially for my girl Sandy, and all the women who’ve taken us to space with them, and the girls who are our future explorers.” Was it is a cheesy publicity stunt to promote her new album? You bet! But it beats waking up to a buzzer.

13. “As Slow as Possible” (John Cage)

The Song That's Outliving Its Composer (and Everyone Else, Too)

© Jens Wolf/dpa/Corbis

Right now, in St. Burchardi church in Halberstadt, Germany, there’s an organ playing a song that has no end—in our lifetime, anyway. Even though the sheet music for minimalist composer John Cage’s “As Slow as Possible” is only eight pages long, the song will take 639 years to complete. It’s part of Cage’s larger exploration of how music exists in time and space; he wrote the piece for an organ because the pipes can last for thousands of years. A machine, called a blower, constantly supplies air, and a weight holds down the pedals. The first three-note chord, which was played in 2003, lasted for a year and a half. The church is committed to playing the song until it’s over. If you can’t wait for the full version, don’t worry: The club remix will drop any day now.

The Song That Brought the Dead Back to Life In 1991, Natalie Cole decided to sing with her late father, Nat “King” Cole. The decision opened a virtual can of worms. New digital technology allowed her producers to electronically engineer the duet with the dead singer, basing it on Nat’s 1951 recording of “Unforgettable.” People argued that the production was unethical, and more than a little creepy—even Natalie’s mom publicly criticized her—but the controversy was eclipsed by the song’s success. The attendant album sold more than 7 million copies and swept the Grammys. Nowadays, everybody sings with dead people: Lisa Marie Presley croons with Elvis; Janet Jackson jams with Michael; and The Beatles reunited to record “Free as a Bird.” It turns out you don’t need a necromancer to communicate with the dead. You just need a decent producer.

The Song That Won 8 Gold Medals Back in 2008, Michael Phelps was the king of Beijing, setting the record for the most gold medals won at any Olympics. What was his secret? His 10,000-calorie-a-day diet? His flipperlike hands? Or perhaps ... Lil Wayne? Before each race, Phelps would tune out the world and tune into his music, removing his iPod earbuds seconds before diving in. One Israeli doctor even went so far as to accuse him of doping because music so enhanced his performance. On The Today Show, Phelps shared that Lil Wayne’s “I’m Me” had a special place in his Olympic playlist. It’s easy to see how the lyrics “There ain’t nothin’ gonna stop me, so just envy it” might resonate with a young man about to race his way into sports history.

The Song That Made Every Link a Surprise Party Rick Astley‘s huge 1987 hit “Never Gonna Give You Up” and its fantastically cheesy music video was meant to live and die in the 1980s, but that’s not what happened, thanks to an Internet prank dubbed “Rickrolling.” Say a coworker emails you a link to a news article or blog. You click on it, but—surprise!—you’re redirected to the video for “Never Gonna Give You Up.” One minute you think you’re about to read a story on health care, the next, a man lip-synching and wiggling in white jeans pops on your screen. The phenomenon began in 2008 on 4chan, but quickly spread across the Internet. Funny, right? Maybe the first dozen times it happens to you. In the last three years, the video has been viewed more than 50 million times.

Watch the Oregon House members Rickroll their colleagues. Explanation here. (OK, here.)

The Saddest Song, According to Science It’s one thing to write a sad song; it’s another thing to pen a song so sad that it teaches scientists the meaning of melancholy. The verve’s 1997 dirge “The Drugs Don’t Work” is about lead singer Richard Ashcroft’s dad as he lay dying in his hospital bed. It’s so depressing that it may affect people physically. In 2006, Harry Witchel, a physiologist at the University of Bristol in England, examined the body’s response to pop music. Of all the songs he studied, “The Drugs Don’t Work” had the most profound impact, slowing down heart rates and breathing. “It works like the emotional state of sadness,” says Witchel.

8. “Pretty Woman” (2 Live Crew)

The Song That Made it Safe to be Weird Al Parodies are tricky in the eyes of the law. While the First Amendment protects free speech, it’s not exactly legal (or cool) to copy somebody else’s work.

The boundaries of the law were put to the test in 1989, when the rap group 2 Live Crew revamped “Oh, Pretty Woman,” by Roy Orbison. The late singer’s publisher, Acuff-Rose Music, which had made a fortune licensing the ditty, was not amused by the filthy, expletive-laden rendition. The publisher sued 2 Live Crew, claiming the group had never been given permission to sample the song. The case made it to the U.S. Supreme Court, which decided in 2 Live Crew’s favor, ruling that the rap version was so different from the original that the group had essentially created a new product. Consequently, parody artists ranging from Weird Al Yankovic to Lez Zeppelin (the lesbian Led Zep cover band) don’t need to fear the law.

Perhaps the strangest result of the “Oh, Pretty Woman” case lies in Justice David Souter’s opinion. Souter appended the lyrics from 2 Live Crew’s song to his text. Lines like “Big hairy woman, you need to shave your stuff,” now reside in law libraries across the country.

7. “The Super Bowl Shuffle” (The Chicago Bears Shufflin' Crew)

The Song That Gave a Beat to Jock Itch The 1985-86 season was a good one for Da Bears. The Chicago team not only dominated the National Football league but also kicked off a strange musical revolution. The team was filled with larger than life characters, including cuddly 350-pound rookie lineman William “The Refrigerator” Perry and spikey-haired punk quarterback Jim McMahon. So it stood to reason, why not let ‘em rap?

The bravely cheesy “Super Bowl Shuffle” was the first hip-hop video ever created by a sports franchise, and it became a huge hit, receiving endless airtime and sales of more than half a million singles. (It was even nominated for a Grammy!) Sadly, it opened the floodgates wide for every pro sports team to rap, sing, chant, dance, and Auto-Tune their own song, giving rise to regrettable chestnuts like “Get Metsmerized” from the Mets and “Ram It” from the Rams.

The Song That Kicked off the Prepster Craze On March 19, 1994, Snoop Dogg appeared on Saturday Night Live to perform his single “Gin and Juice.” Little did he know, he’d be starting a fashion frenzy. The next day, Manhattan stores sold out of the XXL-oversized red, white, and blue Tommy Hilfiger rugby shirt that Snoop wore on TV, and sales of Tommygear rose by $90 million that year. Although there were rumors that Hilfiger was displeased his preppy label had become an urban phenom, he actually courted the new demographic. Hilfiger tweaked his brand to give it a more hip-hop feel, adding brighter covers and giant logos. He even invited rappers Puffy and Coolio to walk the runway during fashion shows. Apparently, Snoop wasn’t the only one with his mind on his money and his money on his mind.

The First Song Aliens Will Hear About four centuries from now, Beatlemania may spread to a galaxy far, far away. In February 2008, for the first time ever, NASA beamed a song, The Beatles’ “Across the Universe,” directly into deep space through the transmitters of its communications network, with the hope that it will fall upon alien ears. The pop tune should reach the North Star, Polaris, in about 431 years. John Lennon’s widow, Yoko Ono, characterized the song’s transmission as a significant event: “I see that this is the beginning of the new age in which we will communicate with billions of planets,” she said. Let’s hope no aliens sample the tune—collecting royalties is going to be rough.

The Song That Killed the Record Labels Radiohead has been defying expectations and pioneering music trends for more than two decades, but in 2007, they became revolutionaries in the business world, too. With illegal downloading running rampant and CD sales on the decline, Radiohead decided to cut out the record companies, middlemen, and price tags altogether. They let consumers download their seventh studio album, In Rainbows (including their hit single “Jigsaw Falling into Place”), directly from their website, asking fans to pay whatever they wished. Although about one-third of the people who downloaded the album took it for free, buyers forked over an average of about $8. Within a year, the album had sold 3 million copies. And with virtually no distribution fees, it was a huge financial windfall for the band. In the years since, other groups have followed suit, and the power of the record companies has continued to dwindle. Giving it away might just prove to be the sales strategy that saves the music business.

The Song That Eases the Anxious Bovine Mind Blasting R.E.M.’s “Everybody Hurts” at 5 a.m. might not seem like the best recipe for increased productivity, but it works for cows. Researchers in the United Kingdom have shown that playing slow, melodic songs can reduce bovine stress, prompting cows to produce nearly a half a pint more milk per day than they would without music. Of all the songs the scientists tested, R.E.M.’s ode to empathy led the list of songs that yielded the most milk, especially when played daily from 5 a.m. to 5 p.m. If you are a lonely cow, living in a barn, with your udders constantly being tugged, maybe it helps to know that everybody cries, and everybody hurts, sometimes.

The Song That Made Singers Obsolete In 1998, Cher created a monster—or rather, her producer did. Auto-Tune, an audio processing technology that fixes pitch and corrects mistakes in musical performances, had been around for years, but few artists used it to any effect. Producer Mark Taylor’s goal was to make a dance song that would appeal equally to club kids and older fans from Cher’s “Gypsys, Tramps & Thieves” days. So he took the singer’s distinctive voice and amped it up with Auto-Tune, adding slip-sliding notes and robotic tones. Taylor was afraid Cher would hate the changes, but she dug them. “Believe” was released in 1998 and went on to become one of the most commercially successful singles of all time, selling more than 10 million copies worldwide and later winning a Grammy Award for Best Dance Recording. Auto-Tune is now a ubiquitous part of pop culture; the diverse musical stylings of T-Pain, Kanye West, Katy Perry, Paris Hilton, and Rebecca Black simply couldn’t exist without it. And singers are just one step closer to being completely replaced by robots.

1. “I Love You” (Barney the Dinosaur)

The Song That Makes Bad Guys Tremble

Why is the opening theme from Barney the most powerful song of the last 25 years? Because it made sure the terrorists didn’t win. In the U.S. military detention camp in Guantanamo Bay, there’s a special spot, known as “the Disco,” where interrogators use music to get detainees to talk. Naturally, death metal is on the playlist, and so is Christina Aguilera. But according to The Guardian, the most used song in the military’s arsenal is Barney’s “I Love You.” Interrogators refer to it as “futility music,” which convinces prisoners that it’s pointless to keep their silence. After listening to the song over and over, detainees start to feel that life is meaningless, and that it’s time to give up. It really works—Just ask any parent.