We've watched enough X-Files to know there are already aliens living among us. Heck, if we're willing to believe former Canadian Ministers of Defence apparently there are four separate alien races already assimilated into our civilization — some of whom have infiltrated the U.S. Government. (Doo-doo de doo-doo de doo)

There are a number of ways us normal humans can react to this realization we're not alone.

1) Freak the heck out.

2) Put on the glasses when Roddy Piper tells you to.

3) Welcome our new intergalactic overlords and celebrate.

The World UFO Day Organization leans towards the third option and has picked July 2, the day that commemorates the "supposed" U.F.O. crash in Roswell, New Mexico in 1947, as World UFO Day.

When the Kree or the Skrull or the Shi'ar or whoever finally reveal themselves, we here at HuffPost want to be on their good side.

So in honour of all the funk-freaky aliens living among us, here are 20 songs to celebrate World UFO Day.

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  • Ella Fitzgerald "Two Little Men In A Flying Saucer"

    In this 1951 novelty song, jazz legend Ella Fitzgerald tells the story of a pair of aliens who come down to Earth to take a look around, decide this planet sucks, then fly away. Can't say we blame them. If "Mad Men" has taught us anything, it's that the '50s were pretty racist.

  • Nas "We're Not Alone"

    You'd expect a first-person alien encounter from someone like Pharrell Williams because he's the sort of guy who wants to do concept albums about "The Day Of The Triffids." But whipsmart street poet Nas? If he believes in aliens, who are we to argue?

  • Creedence Clearwater Revival "It Came Out Of The Sky"

    When Jody gets knocked off his tractor by something that falls out of the sky everyone tries to lay claim to the mysterious object — the government, the Vatican, the media. He's willing to give it up, but for the right price — which is $17 million.

  • Katy Perry feat. Kanye West "E.T. "

    It's good to know that if aliens invade the Earth, Katy Perry will be right there willing to give herself up to them sexually for the sake of peace and humanity. Thank you in advance.

  • Elton John "I've Seen The Saucers"

    Elton John's lonely astronaut masterpiece "Rocket Man" gets most of the attention when it comes to the pianist's space-based songs, but "I've Seen The Saucers" is far more the real deal. The song, from the 1974 album "Caribou," includes John's hopeful wish that the aliens he's flying across space with "can get me back before the morning light."

  • The Timelords "Doctorin' The Tardis"

    KLF members in disguise, Bill Drummond and Jimmy Cauty composed this epic 1988 dance jam in honour of everyone's favourite time-traveling Dalek fighter, Dr. Who. Considering how many times the good Doctor has saved the earth from alien obliteration at the very least he deserves his own theme song.

  • David Bowie "Loving The Alien"

    If you were to speculate which people on this planet might have actually had sex with an alien (or, for that matter, actually be an alien), David Bowie would be firmly in the 99th percentile. The scene at the end of this video where a blue-skinned Bowie gets kissed and then rockets into space is particularly compelling evidence.

  • Klaatu "Calling Occupants Of Interplanetary Craft"

    Canadian prog rockers Klaatu had a simple message for alien invaders with their 1977 hit — "we are your friends." When the alien reveal happens that probably won't actually be true, but we appreciate the sentiment.

  • Dr. Octagon "Aliens"

    Dr. Octagon, better known as mad bananas rapper Kool Keith, contemplates the reality of an alien abduction during this rap-ska party jam filled with pseudo-scientific jargon. It's somewhere out there.

  • The Orb "Blue Room"

    British ambient house heroes The Orb blew minds when they released this 39-minute, 57-second space groove single in 1992. The song's title is a reference to a rumoured holding center in Ohio's Wright-Patterson Air Force Base where true believers think extraterrestrial spacecrafts and bodies are being housed.

  • Sheb Wooley "The Purple People Eater"

    Aliens have dreams, too. And sometimes a one-eyed, one-eared flying purple people eater just wants to be in a rock 'n' roll band making music using the horn in his head. Like in Sheb Wooley's 1958 hit.

  • Styx "Come Sail Away"

    The '70s were a good time for space rock and prog balladeers Styx were among the best at it. The band's 1977 power ballad about sailing away into the stars made it all the way to #8 on the Billboard chart. It was later revived by an amazing Cartman performance in "South Park."

  • Megadeth "Hangar 18"

    Another song based on conspiracy theorists' favourite room — the mythical holding center at Ohio's Wright-Patterson Air Force Base — the video for "Hangar 18" features U.S. military officials jailing and torturing aliens. And members of Megadeth.

  • The Byrds "Mr. Spaceman"

    It's fitting that cosmic country rockers The Byrds would write a song about an alien encounter. It's equally fitting they'd then get bummed out when they woke up after the encounter and realized the aliens didn't take them along on an adventure into space.

  • Blink 182 "Aliens Exist"

    For whatever reason pop-punkers Blink-182's "Aliens Exist" is the go-to song for numerous animated fan video creators. True to Blink fan form, they generally end in an anal probing.

  • Sufjan Stevens "Concerning The UFO Sighting Near Highland, Illinois"

    This song might actually be more Christian rock than alien rock. Which, if <a href="http://www.jesuswasaspacealien.com/" target="_blank">THIS website</a> is to believed, is perfectly consistent.

  • Husker Du "Books About UFOs"

    Everyone's got a special interest and if one woman's happens to be heading down to the library to pick up books about UFOs, so be it. Don't judge.

  • Yes "Starship Trooper"

    This prog song from 1971 is named after a novel by sci-fi writer Robert Heinlein rather than that bad movie with Denise Richards, though it's got nothing to do with either. Rather, it's about a supernatural power — maybe "Mother Nature," maybe "God," maybe who knows what — that protects the Earth.

  • Graham Parker "Waiting For The UFOs"

    British rocker Graham Parker's song is a near-perfect anthem for World UFO Day, addressing skeptics, the government and the evidence (or lack of) in one slightly caustic song that mostly pushes to everyone to think about humanity.

  • Mustard Plug "I Made Love To A Martian"

    Add ska band Mustard Plug to the list of acts who've sung about sexing up space aliens. The song's protagonist experiences some angst about having done the nasty with a Martian, even exclaiming "What the hell is wrong with me?!" at one point. But then he marries said alien, so clearly he got over it.