Pondering the meaning of computer compositions

November 16, 1997|By Glenn McNatt

IN NINTH GRADE, the tedium of biology class was offset only by the high jinks of my lab partner, a fellow of infinite wit who, among other things, taught me to read miniature scores of Beethoven symphonies, which we hid behind our textbooks while the teacher droned on about amoebas.

One day my chum announced he was working on his own symphony. I was suitably impressed. But after weeks passed and I heard nothing further, I asked how it was going.

"I don't know enough to write a symphony," he admitted rather sheepishly. "It's more complicated than I thought."

In the callowness of youth, I thought: Complicated? What's so complicated? Just do like Beethoven -- Da Da Da Dum!

Years later I was required to study the formal structures composers use to develop their musical ideas -- sonata-allegro, theme and variation, rondo, fugue and passacaglia. And yes, it is complicated.

But perhaps my old lab chum was too easily intimidated after all.

Now comes news of a clever computer program called EMI that can create music in the style of J.S. Bach so convincingly that audiences are persuaded it is the real thing.

EMI, which stands for Experiments in Musical Intelligence, is the brainchild of David Cope, a composer at the University of California at Santa Cruz.

Cope originally created the program to help generate ideas for his own compositions. But his electronic helpmate, like the artificial intelligence Hal in the movie "2001," soon took on a life of its own.

Cope taught EMI to scan pieces by Bach and pick out the composer's musical "signatures," then create new pieces employing the same forms as the original.

To his surprise, the machine produced amazingly persuasive imitations.

Now theorists are pondering the implications of EMI for the way we judge musical greatness. If a computer can write music nearly as engaging as that of giants like Bach and Mozart, what is it about their music that makes it so special?

A machine, after all, has no knowledge of what we call "life" or the world. The paradox of EMI is precisely that it can create engaging music without having anything whatever to say.

The idea that a machine can create art -- even if it is not great art -- is profoundly disturbing to many people. It seems to imply a diminished significance for human creativity or, conversely, suggest that our conception of art as a conduit for deep spiritual truth is sadly misplaced.

Meaning and music

Certainly the question of "meaning" in music, and how music communicates those meanings, is one of the most perplexing problems in all art. The question is particularly complicated because instrumental music is nonrepresentational and autonomous; it refers to nothing outside itself.

Music develops according to its own laws, and the truths that it conveys are comprehended on a purely musical level. Consequently, it is difficult even to describe a musical experience in words, much less assign it any specific meaning.

The "meaning" of Beethoven's Fifth Symphony or W. C. Handy's "St. Louis Blues" can be understood only by listening to them, because the act of comprehension itself depends on intuitive value judgments the listener makes as part of the musical communication.

All of which raises the question of what a machine can possibly "mean" when it composes music.

The ghost in the shell

The paradox reminds me of last year's cult movie "Ghost in the Shell," the animated sci-fi fantasy about a future in which people have become so dependent on technology that the line separating human and machine intelligence has virtually disappeared.

The protagonists are two police officers -- Kusanagi and Batteau -- whose powers have been greatly augmented by the addition of cybernetic bodies and computer-enhanced brains.

Kusanagi -- a sort of female counterpart to TV's "$6 Million Man" -- has been so altered by technological enhancements that all that remains of her human self is the merest "ghost in the shell" of a machine-made body and brain.

The absurdly complicated and prolix plot revolves around the agent's efforts to catch a mysterious computer hacker. When they finally succeed, they discover the culprit is not a person at all, but rather a renegade computer program that has taken on a life of its own -- though unlike Hal of "2001," this one's motives are mostly benign.

What's intriguing about this futuristic tale is the idea that intelligence, personality, even character may all be reducible to a "signature" that can be simulated by machines, which then may produce imitations that are all but indistinguishable from real life.

That presumably is how a machine like Cope's can produce music that suggests an experience of life. The machine knows nothing, but there is an entire cosmos embedded in the tonal relationships that make up Bach's musical signature.

In this sense it is possible to surmise that the master's ghost lives on in the shell of Cope's machine.

Pub Date: 11/16/97

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