In the 1920s, Alfred Sloan ran General Motors. When he convened his management team to explore whether to open a plant abroad, they all approved the move. Sloan replied that he wouldn’t make a decision until he heard some disagreement. He wanted the best judgments to flow from clashing viewpoints.

Consigliere Bill Campbell, guru to Silicon Valley, played a key role in getting Apple’s iconic “1984” ad on the air to introduce the Mac during Super Bowl XVIII. Advertising Age calls that ad the best commercial ever made.

To create a more collaborative culture, CEO Gregg Steinhafel encourages Target's 365,000 employees to harness social media. The retail giant has developed an internal online platform that enables workers at all levels to post comments, share ideas and engage in Facebook-like interaction with each other.

When Maestro Wolfgang Heinzel stands before the Merck Orchestra, he may look like an authoritarian leader, commanding musicians from his podium. But Heinzel doesn’t actually know how to play the instruments himself—“in the same way a leader in an organization can’t do everyone’s job,” says Jon Chilingerian. Here is what maestros—and good leaders—understand.

After a diagnosis, patients at the Mayo Clinic meet with a team of specialists who help them understand what’s happening so they can decide about treatment together, says president and CEO Denis Cortese. This kind of teamwork is the stock-in-trade of Cortese, who won last year’s top leadership award from the National Center for Healthcare Leadership.