The Most Important Song Ever Written

Led Zeppelin - Stairway to Heaven.

No explanation needed, all other answers are incorrect.

John Lennon - Imagine

Has any other piece of music managed to tackle an array of topics so unbelievably far-fetched it actually qualifies as science fiction? I can't imagine the unadulterated drug abuse necessary to dream up a such a heaping slice of craziness.

John Lennon's "Imagine". I know, it's a bit cliche, but when I read the question it was the first song that subconsciously popped into my head, even though I tried to force something else in it's place. "No...please don't be 'Imagine'". But it was there, and the fact that it was against my conscious will means (for me) that I've got to go with it.

Ok, so why is it important? I don't know. Maybe in a world full of makeup, job titles, and status symbols, there remains one undeniable desire in all of us...and that is for this world that we live in to progress, and not digress. Sometimes it's hard to filter through the crap in our daily lives to focus on what is really important. The test of truly great song is in its ability to convey a timeless idea. According to this criteria, "Imagine" reigns king.

Bob Marley- War

This man was the poignant musical voice of world conscience in the 20th Century. This was his strongest message.

"We are the World" - A breakthrough in social conscienceness; leading to things like Live-Aid:

Written By Michael Jackson back when he believed in helping kids. Lyrics say it all.

We are the world

We are the children

We are the ones who make a brighter day

So let's start giving

There's a choice we're making

We're saving our own lives

It's true we'll make a better day

Imagine there's no heaven -
It's easy if you try.
No hell below us,
Above us only sky.
Imagine all the people
Living for today, Ah-Ha-Ah-
Imagine there's no countries,
It isn't hard to do.
Nothing to kill or die for
And no religion too.
Imagine all the people
Living life in peace,
You-Oo-Oo-

You may say I'm a dreamer,
But I'm not the only one.
I hope some day you'll join us
And the world will be as one.

Imagine no possessions,
I wonder if you can.
No need for greed or hunger,
A brotherhood and sisterhood of man.
Imagine all the people
Sharing all the world,
You-Oo-Oo-

You may say I'm a dreamer,
But I'm not the only one.
I hope some day you'll join us
And the world will live as one.

Sam Cooke -- A Change is Gonna Come

One of those timeless combinations of music and lyricism; smooth and rich, and as relevant today as it was during the Civil Rights movement.

Sarah McLachlan - World on Fire

This music video speaks for itself.

The Clash - Know Your Rights

...
Number 1
You have the right not to be killed
Murder is a crime!
Unless it was done by a
Policeman or aristocrat
Know your rights

And number 2
You have the right to food money Providing of course you
Dont mind a little
Investigation, humiliation
And if you cross your fingers
Rehabilitation

...

Number 3
You have the right to free
Speech as long as youre not
Dumb enough to actually try it.

...

It's been mentioned three times already so to repeat it may be cliche, but here's why I believe that Imagine should qualify:

John Lennon made a haunting pop song that brought the idea of a single secular and cosmopolitan world society to the masses. No other song that I'm aware of has done so much to instill a vision of an attainable utopia into the popular imagination. With just a few verses he transcends all of the major "mind-forged manacles" that keep society in a state of perpetual conflict.

I generally react negatively towards sentiment, and so I sort of groaned when I realized that I couldn't possibly pick any other song - but it's gorgeous and inspiring, and cuts so deeply into the heart of things that it resists cliche - sometimes, when you listen to it, time stands still and you feel the meaning of peace and beauty.

I'm noting that this is the most important song ever written. I would have to say that is "Happy Birthday". Sure, it could be a pop/rock song, Lennon's "Imagine" was my first thought. However, when you look at the most significant and recognized song, "Happy Birthday" has been part of everyone's childhood and is sang more across the board - from children in a Chuck E. Cheese to Marilyn Monroe. It also pre-dates everything on here.

Rush - 2112

The anti-Imagine.

Tenacious D - Tribute

Enough said.

The Star Spangled Banner - Francis Scott Key Arguably the most influential American song ever written and has been around for nearly 200 years (in one form or another).

There's a lot of great songs in the world, but few are recognized so universally as "Amazing Grace". It's a song loved & cherished by millions world-wide.

Ring Around the Rosie
A pocket fully of posey...

...a song that gives kids a history lesson and fun at the same time. One that has been traditionally handed down for ages and probably will be forever.

CHEAP TRICK'S SURRENDER

The beginning of the refrain:"Mommy's alright, daddy's alright, they just seem a little weird..."
speaks to the generational divide between teenagers and their parents and the sone also teaches kids that it's ok to rebel and choose your own path but to have respect for the hand that feed:

"Surrender, surrender, but don't give yourself away"

It's a beautiful timeless message.

Pomp and Circumstance

Who hasn't heard it at least once in their lives? It was originally intended for any somber occasion, but it's come to represent, in and of itself, the act of bettering oneself through the process of learning. It's hard to think of something more important than that.

The most important song ever written would have to be Imagine.

Imagine no possessions
I wonder if you can
No need for greed or hunger
A brotherhood of man Imagine all the people
Sharing all the world

The song speaks to us of a better way of life. Lennon had a vision of a world where there was no greed, where people helped one another instead of always trying to have more and be better than others. He "imagined" a world where we accepted others for who they were, with no judgment. The song reflects on having no religion, as the wars fought in the name of religion have caused more deaths and destruction than any God would have wanted. The song asks us to "Imagine all the people, living life in peace". It is hard to do, but if more would try, I imagine things really could be better.

The Illiad

Although we think of this as a book, it was originally composed and transmitted as a song. The Illiad stands as the foundation of literature for the western world, a foundation upon which our culture has been built. Without the Illiad and other epic poetry we would not have developed our philosophy, our politics, or even such forms of communication as Newsvine.

The Rainbow Connection - by Paul Williams and Kenneth Ascher

In such a cynical age, this song reminds us that it is still okay to dream.

In song there are no partisans
nor barbed insults employed.
Politics meet with pleasantry
and rhyming verse enjoyed.

Yet in protest or in praise
may an oft rare chorus rise, to challenge our assumptions
and uncloud our darkened eyes.

Though the strains of One Tin Solider
gave voice to war's great price,
and the notes that we Imagine
intoned "security's" sacrifice,

Is simply one of thousands
somehow of more significance
or is song itself a gift divine
and harmony our penance?

In chords and notes and melodies
may we find peace at last
for where human hearts may fail
music's sweet refrain holds fast.

"My anaconda don't want none unless you got buns hun"

Sir Mix-A-Lot, Baby Got Back"

This song made women shake their rumps on the dance floor...and I love rump shaken.

Alright, I have a lot of opinions here, but the question was asking for an absolute. So here is my answer: Happy Birthday to You. This little pop gem from the 1890s (the very first Billboard number one single), has reached across practically every culture around the world. It is one of the most recognizable signs of celebration anywhere.

This song is a message of optimism in a crumbling world. It says, in essence, "I'm glad you're alive today. That's an accomplishment we should all celebrate." If only everything worked that way.

Johnny Cash - A Boy Named Sue

Imagine a world where people didn't have the guidance of Mr. Cash's vivid story of understanding between a young boy and his father. Boys would be named Sue and probably thrown into jail with all the head bustin' done when gals would giggle and guys would laugh.

Even in a world with "A Boy Named Sue," poor boys named Sue wouldn't know how to introduce themselves. "Hi. I'm Sue." "Good afternoon. My name is Sue." Nothing has a better ring than "My name is Sue! How do you do! Now your gonna die!"

For these reasons any many more I don't have the space to share, "A Boy Named Sue" is the most important song ever written.