It’s appropriate that when Tricia Tunstall first entered the world of Gustavo Dudamel, her guide was the daughter of the musician Dudamel regards as one of his spiritual mentors: Leonard Bernstein.

In winter 2008, Jamie Bernstein, a writer and broadcaster, went to hear Dudamel conduct the Israel Philharmonic at Carnegie Hall in a program that included her father’s Concerto for Orchestra (“Jubilee Games”). She brought along her friend Tunstall, a New York musician, music educator and author of the just published book Changing Lives: Gustavo Dudamel, El Sistema, and the Transformative Power of Music.

Jamie Bernstein had first spotted Dudamel in a YouTube clip conducting Venezuela’s Simon Bolivar Youth Orchestra performing “Mambo” from West Side Story. Speaking of Dudamel, she told Tunstall: “This is everything my father meant.”

“She says that a lot,” Tunstall said, speaking by phone from her New York City-area home. “Meaning the combination of musical virtuosity, passionate communication between members and the audience, and passionate love for the communicative expressiveness of music.”

Changing Lives weaves together several interrelated stories. It chronicles the origins and growth of Venezuela’s acclaimed El Sistema national music education program (which has trained about 400,000 children, many among Venezuela’s poorest), profiles its charismatic founder-leader, Jose Antonio Abreu, and analyzes the program’s growing international influence, as communities from Scotland to Baltimore and L.A. have implemented programs inspired by El Sistema (Spanish for “the System”).

But Tunstall necessarily devotes a good chunk of her book to the story of the 31-year-old Dudamel, who is El Sistema’s most famous graduate and a walking symbol of how exposure to classical music at an early age can expand or even radically alter a person’s life possibilities, and touch the lives of others in their communities.

Although much of the book’s background will be familiar to classical music aficionados through the profuse media coverage generated by Dudamel’s career ascent — 60 Minutes alone has devoted multiple segments to the young maestro — Changing Lives is the first work to pull the entire tale together in one volume, “related so eloquently”, in the words of L.A. Phil President Deborah Borda.

Tunstall said she had two main objectives in writing her book, which has received praise from the likes of Richard Holloway, founder of Sistema Scotland (“Read the book. Join the movement. Change the world.”) and Quincy Jones (“Essential reading for every one of us who cares passionately about our neediest children.”). She wanted to tell a compelling tale of how El Sistema, started on a shoestring budget in 1975, overcame huge obstacles to achieve its stature as a world leader in arts education. And she wanted to proselytize on behalf of its mission.

As a music educator herself, Tunstall said, she knows “innately” the validity of El Sistema’s educational and artistic principles. “But the Sistema puts it forward in a community oriented way, which is I feel a really important and new message,” she said. “I would like to get that message out as widely as possible, not only to music educators but also to all educators and to people who are looking for new and effective ways to address the cycles of hopelessness and despair that are so endemic to poverty.”

Those cycles, Tunstall believes, are visible in the decades-long decline of U.S. music education. For the privileged few, excellent teachers and private conservatories are available. For the rest, budget cuts and bureaucratic indifference have gutted public arts programs, or wiped them out entirely.

“And so that Bernsteinian vision of having a love for and an appreciation of classical music be something that reaches every child, that’s barely anywhere,” she said. That, in turn, has diminished the presence of classical music as part of US popular culture, she added.

Some help is on the way, Tunstall believes, in the form of emerging music education programs and youth orchestras in cities like Los Angeles and Baltimore that are taking El Sistema’s ideas and adapting them to suit their own local needs and circumstances. How much help they can offer, only time will tell.

“I feel like we are so ready for this idea, and people are so hungry for this idea,” she said.