The man who invented the Apple (Nasdaq: AAPL) way of doing business has passed away. Oh, don't worry -- Steve Jobs is fine. Rest in peace, legendary Sony (NYSE: SNE) leader Norio Ohga.

I'm serious about the Apple business thing. Cupertino famously runs a number of interconnected but seemingly separate product lines to form a self-reinforcing ecosystem. More iPhone sales raise interest and sales for the iTunes media hub, perhaps leading the same consumers back to the trough for another iPod, maybe an iPad, and eventually a Mac of some kind, too.

Then, the fully equipped Apple fans go out into the world and encourage their friends and neighbors to follow along. Word-of-mouth advertising and taste-making customers are powerful assets, and Jobs goes out of his way to create these raving evangelists on the street.

As it turns out, Ohga did it first; Apple just perfected the model. As CEO during Sony's golden years in the 1980s and 1990s, Ohga insisted on adding a record label and a movie studio to augment and cross-fertilize the core electronics business. "Hardware and software are two wheels on a car," he often said.

Under Ohga, Sony embodied that ideal for nearly a decade. The Walkman was once as cool as today's iPods and iPhones. And in a market full of seemingly identical TV sets, VHS players, and audio receivers from Panasonic (NYSE: PC), JVC, Hitachi (NYSE: HIT), and others, you'd pay extra for the Sony brand. Not necessarily because the product was better, but because it made you feel better.

That's exactly what Apple does today. Instead of producing media in-house, Apple runs the leading marketplace for digital content, while enjoying close ties to Walt Disney (NYSE: DIS) through Jobs' spot on that company's board. The rest of what Jobs does harks straight back to Ohga. As Apple lives and dies by sleek, soft contours and monochromatic color schemes, so did Ohga enforce Sony's equally emblematic matte black designs. When Sony introduced the CD in 1982, it made sure that Beethoven's Ninth Symphony could fit on a single disc at Ohga's personal insistence.

Does that attention to detail remind you of somebody?

Sony was never the same again after Ohga stepped down in 1999, just as Apple may lose its soul when Jobs moves on. Steve Jobs just lost a kindred spirit, and perhaps even his personal role model.

A glance at Sony's past might tell you something about Apple's future. The best way to stay on top of Apple's trajectory is to add the stock to your Foolish watchlist. A steady stream of updates will keep your finger on Cupertino's pulse.