This is all from http://www.datasync.com/~booda/mcap.html. As I understand it it's an original work and therefore copyright someone, but having originated on USENET (I think) distribution isn't generally frowned upon.

It's not commonly known, but while he was writing songs in the late 60's and early 70's, Don McLean was auditing Computer Science courses at Harvard in order to gain an understanding of what was then primitive music software. There he learned the wondrous legends from the Dawn Time of Cybernetics: of Babbage, Turing, and Hopper. There he witnessed the original Mark II and its famous moth. There he wrote his famous song, "Vincent", about the popular starfield screen saver (which he erroneously believed was invented by J.Vincent Atanasoff). There, too, he became acquainted with a teenage prodigy with whom he shared some classes; a boy whom McLean would later characterize as "Satan", who would seize control of the entire world's cybernetic industry. That boy was the young Bill Gates. McLean, spiritually chilled by his encounters with the ruthless Gates, experienced an uncannily accurate prophetic vision a la Nostradamus and wrote a song, "American Pi" (frequently misspelled "Pie"), reminiscing about the Golden Age of Computing, its contentious present (in 1969) and its apocalyptic future. Woven into the vision are observations and commentaries on such varied subjects as Kurt Cobain, James Joyce and General Motors. The following is an interpretation of the cryptic lyrics of this enigmatic song.

A long, long time ago...

Computing can be said to have originated with Stonehenge or earlier; but remember, McLean here is speaking from a prophetic dream. "A long, long time ago" is in fact the era before 1969, the year that the Internet, the modern Operating System and "American Pi" itself were born. (This lyric also anticipates the use of Microsoft technology by George Lucas.) JaneBer@aol.com pursued another lead on this haunting beginning. In her words, it "appears now to be a reference to the Garden of Eden, with Gates trying to establish himself as Adam. And we all know what fruit Adam consumed..."

I can still remember how
That music used to make me smile.
And I knew if I had my chance,
That I could make those people dance,
And maybe they'd be happy for a while.

McLean was eventually unsuccessful in his pursuit to safeguard copyrights of musical material from computer duplication. Ironically, his efforts at Harvard in the 60's and 70's may have inspired Gates to formulate a method of compromising these copyrights.

But February made me shiver,
With every paper I'd deliver,
Bad news on the doorstep...
I couldn't take one more step.

February, 1975 marked the delivery of BASIC to Altair Systems, the first step on the road to World Domination for Bill Gates and Microsoft.

I can't remember if I cried
When I read about his widowed bride

A clever play-on-words. The "wi(n)dowed bride", is, of course, the IBM PC. IBM's founder, Thomas J. Watson, died suddenly in 1943 when he was crushed by one of the world's five PCs (which at the time weighed 1.5 tons).

But something touched me deep inside,
The day the music died.

UNIX time calculations are valid on most processors (i.e., those which store the variable time_val as a 32-bit signed integer) for 2^31 - 1 seconds past 00:00:00 GMT, 1 January 1970 (which coincidently was the moment that "American Pi" was sent to the publisher), or until 03:14:07 GMT, 8 July 2038, when the UNIX time registers will overflow. July 8, 2038, we shall see, will be thought of by future generations as the Day the Music Died.

So bye bye Miss American Pi,

McLean here decries the strict syntactical rules enforced by the spellchecker in Microsoft Word. Random arrangements of characters, or "Pi", would never be allowed by automatic spellcheckers and would be replaced by similar but inappropriate legal words. (As an example, "goan" would be replaced by "goad", and "frig" by "fig"; James Joyce would never have been a great author had he used Microsoft Word.)

Drove my Chevy to the levee but the levee was dry.

A sly chuckle aimed at software used in General Motors (and other manufacturer's) automobiles; even the slightest moisture can destroy the car's computer and render the vehicle worthless. McLean is willing to risk driving his car near the levee, but only because the levee is dry.

Them good ol' boys were drinkin whiskey in Rye

Ryebrook, NY, is where a group of top-level IT executives gathered (no doubt with copious amounts of fine adult beverages) to decide the format of Windows 95 and therefore the hierarchy of the Net for the next ten thousand years.

Singing "This'll be the day that I die,
This'll be the day that I die."

When the time registers overflow on 8 July 2038, all UNIX-based processes will die. (I don't know about you, but I'm sure not going to be wearing a UNIX-controlled pacemaker then!)

Did you write the book of love,
And do you have faith in God above,
If the Bible tells you so?

A reference to Waite Group Press, publishers of both the Microsoft/Windows Bibles and Love Bytes, paeans to the slavish adoration which they pay towards their deity, Bill Gates.

Now do you believe in rock 'n roll?
Can music save your mortal soul?
And can you teach me how to dance real slow?

You don't know what slow dancing is until you try to play your Manhattan Transfer .wav's on a 386SX running Windows.

Well I know you're in love with him
'Cause I saw you dancing in the gym
You both kicked off your shoes

...i.e., they're down to their (Win)Socks.

Man, I dig those rhythm 'n' blues
I was a lonely teenage broncin' buck
With a pink carnation and a pickup truck

Carnation, WA is the site of Gates' soon-to-be-completed pink stucco Xanadu. By a cryptic coincidence, it is also the last resting place of that human bucking bronco, Bruce Lee and the place where Kurt Cobain "shot up" just before driving off in his light utility vehicle ("pickup truck") to commit suicide.

But I knew that I was out of luck
The day the music died
I started singing...

Now for ten years we've been on our own

In 1980...or by the AT&T calendar, 10 UE (Unix Epoch)...IBM bypassed UNIX, turned to Microsoft for its operating system, and the age of the PC dawned. From 1970-1980, UNIX was "on its own" with a virtual monopoly on the OS market.

And MOS grows FAT on a rolling stone

There are several interpretations of this mysterious statement. The Microsoft OS (MOS), Windows, has "grown fat" consistently in terms of market share since 1980, thanks largely to biased comparisons with other OS's using such benchmarks as whetstones and Dhrystones. However, as McLean is cynically suggesting, people who live in glass houses (i.e. with lots of Windows) shouldn't throw stones, or even roll them fast. On the other hand, Ken Wright (koala@main.citynet.net) points out that MS-DOS 2 imposed a File Allocation Table (or FAT) structure onto hard disks. The FAT structure was designed for floppies of only 360K or less, and of course the early hard drives, which weighed around 14 pounds (or, in British usage, a stone). The FAT, after installation of Windows, would certainly be overwhelming. Conversely, Rolling Stones have gotten fat on MOS; see below. The following passage is a hazy rendition of McLean's vision, told in the past tense, in a manner similar to Dante's Divine Comedy. Frequent references are made to the "King", the "Jester" and "Satan". The King, as we shall see, is (or was) AT&T; the Jester is Apple/Steve Jobs (remember, Apple was founded on April Fool's Day), and Satan is, of course, Bill Gates.

But that's not how it used to be
When the jester sang for the King and Queen

Steve Jobs cut his teeth on the "blue box", a device which "sang" the 2600Hz tone which allowed him to rip off AT&T for thousands in long distance calls.

In a coat he borrowed from James Dean
And a voice that came from you and me

The image Apple projected in the Macintosh ad campaign was an odd hybrid of a denim-clad, outlaw-like Rebel Without a Cause and a typical, computer-illiterate Everyman.

Oh, and while the King was looking down

AT&T suffered from a number of investigations and corporate scandals in the 70's, leading eventually to divestiture in 1983.

The jester stole his thorny crown

Before Microsoft, Jobs and Apple were the only challenge to AT&T's market lock.

The courtroom was adjourned,
No verdict was returned.

This is a reference to the legal hemming and hawing leading to the Sporkin Opinion.

And while Lenin read a book on Marks,

Following the tragedy at the V. I. Lenin Reactor at Chernobyl, U.S. technology firms (including Microsoft) scrambled to introduce their products into the former Soviet market. Even Netscape has tried to market Mozilla Web servers in Russia, including with each package a list of suggested Book-marks.

The quartet practiced in the PARC

The "quartet" consists of Gates, Paul Allen, Jobs and Steve Wozniak. (Actually, a pair of duos, if you think about it.) Michael Haynes (mhaynes@bgsuvax.bgsu.edu) spotted the reference to the Xerox/PARC facility which developed a pre-MS Windows/pre MacOS windowing operating system.

And we sang dirges in the dark
The day the music died.
We were singing...

Helter Skelter in a summer swelter

Microsoft has made a headlong rush to release Windows 95 by its summer deadline, even though 32-bit compatibility is absent, making the product useless.

The birds flew off with the fallout shelter
Eight miles high and falling fast

Refers to the UNIX editor EMACS (Eight megs and constantly swapping). The relevancy is to the constantly changing operating system background of UNIX, missing in all MS products except for NT. This causes MS products to fall from grace in the eyes of most EMACS users. (a.crl.com@A.crl.com (trohling) (hmm...))

It landed foul on the grass
The players tried for a forward pass
With the jester on the sidelines in a cast

Of course, Microsoft is not alone in its inability to be fully compatible with UNIX usages, such as casts. McLean shows here the frustration of trying to pass arguments using a Mac C++ compiler, and winding up throwing past the sidelines.

Now the halftime heir was sweet perfume

What with technological advances, it is estimated that the time it takes a microprocessor to execute an instruction halves every 18 months. Yet technological "advances" at Microsoft involve increases in execution time and memory usage! Something smells here, and it ain't Chanel No. 5. One contributor also notes the astonishingly accurate prediction of the birth of the Microsoft heir to Gates in the mid-point of his life, a development which must smell sweet to him...until it comes time to change diapers. Of course, this assumes Gates will provide reliable product support.

While sergeants played a marching tune

Let's not forget who started us marching down the ol' Internet road. One hint: check their domain.

We all got up to dance
Oh, but we never got the chance
'Cause the players tried to take the field,
The marching band refused to yield.

Between them, Microsoft/UUNET and Apple/AOL are just a few yards short of putting the Net Ownership game in the bag.

Do you recall what was revealed,
The day the music died?
We started singing

And there we were all in one place
A generation lost in space
With no time left to start again

McLean has clearly experienced the futility of trying to use a Memory Manager with Windows, then being unable to save his thesis document generated in Microsoft Word after running out of storage.

So come on Jack be nimble Jack be quick
Jack Flash sat on a candlestick
'Cause fire is the devil's only friend

Mick Jagger should catch a lot of heat for selling (for $12 million) the rights to "Start Me Up" to Microsoft for the Windows 95 promo campaign. But then what can you expect from the man responsible for the AOL Interview Fiasco?

And as I watched him on the stage
My hands were clenched in fists of rage
No angel born in hell
Could break that satan's spell

Who could not feel rage at watching Gates' theatrical presentation at the official unveiling of Windows 95, complete with a 3D virtual simulation of none other than Jay Leno, whom Aaron Barnhart called part of a "match made in hell"?

and as the flames climbed high into the night
To light the sacrificial Write

One contributor perceived the horrific message implied in these lines. MacWrite (later Claris Write), the original Mac word processor, was "sacrificed" to the market dominance of Microsoft Word. Naturally, highly negative responses ("flames") from Mac users only served to whet Bill's determination to take over not simply the IBM world, but Macintosh as well.

I saw satan laughing with delight
The day the music died
He was singing...

The song concludes with a touching lament about the rise, decline and fall of the vast CyberWasteland which is USENET.

I met a girl who sang the blues

Doctress Neutopia.

And I asked her for some happy news

McLean and Gates were at Harvard at about the same time as Kibo.

But she just smiled and turned away
I went down to the sacred store
Where I'd heard the music years before
But the man there said the music wouldn't play

A touching complaint about McLean's frustrated attempts to play the .au's he downloaded from alt.binaries.sounds.music with the Off-the-Shelf software he bought from Microsoft.

And in the streets the children screamed
The lovers cried and the poets dreamed

Over twenty years ahead of its time, an uncannily accurate description of talk.bizarre.

but not a word was spoken
The church Bells all were broken

Alert reader Tim Legg observes that this line could be describing a puzzling characteristic of the PC-XT's made in the early 1980s, where the ASCII bell was almost a two second beep. The ASCII bell character on these XTs was the character 04H. But on Pentiums, the ASCII bell is a nearly inaudible click. One could say that the bells are broken since someone didn't calculate for the higher processor speed of a Pentium over an XT. Another interpretation is that AT&T's (Bell's) UNIX monopoly was broken with the IBM adoption of Microsoft's OS. (Another, far more sinister interpretation is that McLean, anticipating the posts on alt.2600, has broken AT&T's RSA key!)

And the three men I admire most
The Father Son and Holy Ghost
They caught the last train for the coast

David Lawrence,Gene Spafford and Ron "Asbestos" Dippold. What a sad vision. McLean is implying that, in the future, even the three most steadfast rocks of USENET may be co-opted by Gates' empire.

The day the music died
and they were singing...

(Oh yes, and if you spell out words with the chord structure, it reads:)

WILLIAM GATES III IS SATAN KILL YOUR PARENTS!