I'm a glass-half-full kind of guy; a lifelong Philadelphia sports fanatic has to be. But even I get down sometimes, particularly when I run up against the Philly "can't-do" mentality.

It's an attitude that sighs at the prospect of a heavy lift. It's why we still have a major highway cutting off access to the Delaware River. And it's why we don't have a ballpark in Center City, putting feet on our streets and disposable income into our economy.

We have a leadership vacuum and, consequently, an allergy to big ideas. We don't tackle the hard stuff. The status quo reigns. If you're a lifer, like me, it can wear on you, man.

But lately I've been finding my spirits lifted by a bevy of newcomers, young disrupters who refuse to sign on to the script. I've introduced you to some of them. Often, they're very young and not yet jaded, so they think nothing of saying to themselves, "There must be a better way."

This is a new thing for Philly. As young, engaged citizens migrate here from higher-cost urban areas (keep those rents rising, Brooklyn!), a cacophony of voices is starting to be heard: Experiment! Think big! Be willing to fail!

One of them is Jeri Lynne Johnson, 40, an African American classical music conductor who has refused to follow conventions. She has built a groundbreaking orchestra at a time when orchestras around the country find themselves in death spirals at least partly of their own making.

Johnson's is called the Black Pearl Chamber Orchestra, and it's a first-rate ensemble, the region's only three-time winner of a Knight Foundation Arts Challenge grant. Its uniqueness is in its sound and its look. Black Pearl has 40 members from a variety of backgrounds - African American, white, Latino, Asian, Middle Eastern - and its playlist has a decidedly multicultural feel.

Its players come from places such as New York's Juilliard School and our own Curtis Institute. So Johnson is proving a principle at work in other arenas, from the military to professional sports: Standards of diversity and of excellence are not mutually exclusive.

"When you have a sea of white faces on the stage, that sends a message," Johnson said. Before their audiences hear a note, too many orchestras are telling them: This is not for you. Johnson has experienced the insularity of her field firsthand, and it made her determined to build something of her own.

Johnson first came to the city in 2000 to be assistant conductor of the Chamber Orchestra of Philadelphia. Seven years later, she was a finalist for a California orchestra's music director position when the head of the search committee told her she didn't make the cut. "You don't look like what our audience expects our conductor to look like," Johnson remembers him saying.

"It was like a punch to the gut," she said. But it didn't take her long to see opportunity in the setback. "I wasn't about to get on my political soapbox and yell and scream, or sue," she said. "Clearly I couldn't change: I'm a young black woman. So the more I thought about it, the more I realized that being outside of the system was the only way to effect the real, radical change the system required."

So, in 2007, Black Pearl was born. Johnson was helped by her willingness to, as she put it, practice "outsider innovation." There were personal factors as well. "Anger is a powerful motivator," she said, referring to the fallout from her experience in California. "I tell people all the time, 'Embrace anger in a positive way to make positive change.' "

Plus, she couldn't fail. "Funding and getting Black Pearl up and running was the exit strategy for my divorce," she said, laughing.

Soon the Philadelphia Orchestra was filing for bankruptcy while Johnson was performing seven concerts a year, paying her players on time and creating a fun experience for her casually dressed, youthful audiences.

Turns out she had an entrepreneurial flair, inherited, no doubt, from her father, Jerry Johnson, a financial executive. As Black Pearl grew, Johnson learned it's easier in many ways to align a start-up with new market realities than it is to get an existing brand to change the way it has always done things.

"Every year, orchestras spend thousands of dollars on ambitious marketing surveys, and I'm convinced they keep surveying because they don't like the results that come back," she said. Those results: Change or die. Sadly, many local institutions seem to be opting for the dying route.

In diversifying the players of the music and the music played, Johnson may be onto something. After all, classical music used to unite the old and the new, the haves and the have-nots. As the New York Times pointed out this month, a century ago, "classical music thrived in a nation of immigrants," and orchestras "were flagship institutions that helped to put American cities on the cultural map."

Today, the Los Angeles Philharmonic is thriving, thanks to the populist flair of its charismatic leader, Gustavo Dudamel. As at Johnson's concerts, a night at the symphony in L.A. doesn't require wearing a monocle or talking pretentiously.

Black Pearl hasn't set a date for its next performance, but it will be in the fall. I'll be there. And I'll be wearing jeans.

Larry Platt's column appears regularly in Currents. He can be reached at larry.platt@gmail.com.