What does it take to be a great leader? In a fascinating series of talks, business leaders, researchers, a famed general, and an orchestra conductor tackle that question from their diverse viewpoints.

Some of their answers will surprise you. Here are seven of their best lessons.

1. Engage people's beliefs.

Why do people spend hours standing in line when a new Apple product is released? Not because they love Apple, but because of what it says about themselves--that they were first, explains Start With Why author Simon Sinek in this seminal talk.

Engage people' beliefs about themselves and about the world and they will be drawn to you and follow you, he says. How do you do that? By focusing first on what you yourself believe and how the work you do grows out of those beliefs. As Sinek says, "People don't buy what you do; they buy why you do it."

2. Let people tell their own stories.

Orchestra conductor Itay Talgam uses video clips in his talk to display the vastly different leadership styles of some of the world's greatest conductors. The most effective elicit the best music by getting out of the way and letting their people shine. He also shares some important lessons such as "Never look at the trombones--it only encourages them."

3. We all have lollipop moments.

Years ago, leadership educator Drew Dudley gave away a lollipop and profoundly changed someone's life for the better--an incident he doesn't even remember. And that's the whole point of his engaging talk. We all change each other's lives all the time and most often we never even know it. It's both frightening and empowering to think of leadership not as a mystical skill only a few of us possess but as something we all do, all the time. Yet, Dudley says, that's exactly what it is.

4. It takes new skills to be a great leader in today's world.

Even though there are more leadership programs than ever before, leaders are seeing alarming failures, reports Roselinde Torres, senior partner and managing director at the consulting firm BCG in her thought-provoking talk. The reason is that in the globalized, digitized, fast-moving 21st century, "relying on traditional development practices will stunt your growth as a leader," she says. 

Instead, today’s great leaders need three capabilities, she says. First, they need to be able to watch and distill trends so that they can see the future and prepare for it. Second, they need to develop relationships with people very different from themselves–people outside their own comfort zones. And third, they must be willing to abandon practices that have been successful in the past. That's tough to do, she says. "It's a leap, not a step." But if you can do it, you'll find you have followers.

5. Improve your tribe.

We're all part of a tribe, or maybe several different tribes, notes USC professor David Logan in his talk. But different tribes function at five different levels ranging from an urban street gang through Zappos all the way up to the historic Truth and Reconciliation Commission that helped South Africa begin its recovery from apartheid. He explains why the best leaders understand all five levels--and work to raise the level of their own tribes.

6. Be willing to learn from anyone.

Four-star general Stanley McChrystal is the former commander of U.S. and international forces in Afghanistan. But, as he explains in his powerful talk, entering into warfare in a post-9/11 world meant using unfamiliar new technology and striving for ways to build camaraderie with soldiers hundreds or thousands of miles away.

Learning to lead a 21st-century fighting force created what McChrystal calls "an inversion of expertise," because many of the younger soldiers under his command understood the technology and the communication channels of the digital world much better than he did. "It forced me to become a lot more transparent, a lot more willing to listen, a lot more willing to be reverse-mentored from lower," he says. 

7. Never stop raising your hand.

After years of striving for equality, women still make up a shockingly low percentage of government and corporate leaders, says Facebook COO Sheryl Sandberg in her thoughtful talk. This is for many reasons, including research that shows that successful men are considered more likable than successful women.

Even worse than that is the fact that women judge themselves more harshly than men do and are less likely to consider ourselves qualified for that promotion or plum job. Women are slower to raise a hand and quicker to put it down again, and liable to take a seat away from the tables of power. Make sure you have a seat at the table, Sandberg advises. And keep your foot on the gas pedal.