Imagine a world in which teaching poor children to play classical music stamped out poverty and created a better society.

Rejoice — we are living in that world!

This, at least, is the belief of many advocates of El Sistema, the network of youth music programs that began in Venezuela in the 1970s, emerged onto the international scene in the early 2000s and has now spawned hundreds of similar programs around the globe.

But just what is El Sistema? That’s a hard thing to pin down, and Tricia Tunstall and Eric Booth don’t quite manage to do it in their new book, “Playing for Their Lives.” They lay out some “key ideas” of El Sistema in Book One (“the citizen artist,” “group intrinsic motivation”), and they elaborate on some “key elements” in Book Two (“radical inclusion,” “music as passion and expressivity”). These include some sound strategies, including peer learning — having children teach each other — and emphasizing music’s pleasure and joy, not always a feature of classical music training.

It’s not until Appendix III, though, at the very end of the book, that the authors actually go about “defining an El Sistema-inspired program” in two pages and six bullet points — information that belongs at the very beginning. Unfortunately, this is symptomatic of the book’s poor organization, which is exacerbated by a lack of clarity on the distinction between journalism and boosterism.

Admittedly, El Sistema itself seems to foster this kind of approach and to remain almost deliberately hard to define. It was founded by Jose Antonio Abreu, who gathered a group of music students in the 1970s to create a new kind of youth orchestra. It’s not at all clear that the program, which according to the book has now grown to 423 learning centers on Venezuela serving more than 500,000 children, was initially founded with the goal of reaching underprivileged kids.

Indeed, this is one of many El Sistema claims that Geoffrey Baker questions in his 2014 book, “El Sistema: Orchestrating Venezuela’s Youth,” which makes the case that, rather than being something radically new, El Sistema relies on time-honored classical-music tropes of authoritarianism and rote drill work. But many classical music lovers feel that the art they love has been given new purpose by El Sistema’s promise to heal society’s ills, and Baker’s criticisms have had surprisingly little resonance. Tunstall and Booth dismiss critics with a general sweep of the hand early on (“Any organization . . . is bound to develop flaws”) and refer periodically to “die-hard skeptics.”

Their goal, in any case, is not to document El Sistema itself, but the spread of its ideas by examining a cross-section of the more than 360 programs around the world listed in Appendix I. The entries include the D.C. Youth Orchestra Program, founded in 1960, with no particular El Sistema relationship. Indeed, none of these programs, even those using the name “El Sistema,” is technically under the auspices of the Venezuelan system that inspired them. The authors call it “a global honors system” — and cheerfully include other, non-El Sistema youth music programs.

None of these programs has yet achieved the quality that the authors insist is a hallmark of the Venezuelan program, whose flagship Simon Bolivar Symphony Orchestra, led by the conductor Gustavo Dudamel, El Sistema’s most famous product, has wowed the world’s concert halls. There are as yet no surveys demonstrating the social benefits of these programs: “It’s simply too soon in the lives of most Sistema-inspired programs to have a substantial show of numbers,” say the authors. But, in their view, this doesn’t matter. For although they stress that “for El Sistema, musical excellence and social inclusion are not two goals; they are one,” the authors are quick to excuse the lack of musical progress in some of its fledgling spin offs. “Radical inclusion,” making room for every single child, is an El Sistema tenet, and if, as a consequence, a group of kids in Romania, Bosnia or Denmark is only just mastering the basics of singing in unison, that doesn’t matter. “The success becomes qualified,” the authors write, “only when value judgments from outside the Sistema worldview are imposed” — evidently forgetting the value judgments they invoked only a couple of chapters earlier.

But you won’t read this book for its logical rigor. “Playing for Their Lives” is so besotted with El Sistema that it verges on cult literature. This is not to deny the achievements of the many people devoting time and energy to helping kids in programs around the world. But the authors, though they traveled to many of these programs, barely even try to give their efforts an objective framework. The outside sourcing is slender and seems not to have extended to corroborative interviews to back up what the subjects say. Over and over again, the book reports on people’s aspirations and the programs’ potential to do good, as if these results had already been realized. “El Sistema is a significant and genuine worldwide movement,” they write. “By the time you read that sentence, it will be true.” And their adulation of El Sistema founder Abreu approaches hagiography. “Like Mahatma Gandhi, like Martin Luther King, Jr.,” they write, “he has shown the world new ways to think about social transformation.”

Working to help kids is a laudable goal. And this book spotlights some inspiring programs that are following the El Sistema ideal to do just that. But it does no one any good to pretend that El Sistema represents a new magic bullet, rather than a motivation for a bunch of people to put a lot of effort into reanimating and extending an existing model.

“It’s not that what we’re doing is so revolutionary or so great,” Dan Trahey, the inspiring leader of the Baltimore Symphony Orchestra’s OrchKids program, once said to me. “We’re putting kids in musical situations for 30 hours a week. They’re going to be able to do something.” Working with kids this intensely in any area — music, carpentry, chess — is likely to have a positive effect. Even the authors of this book concede, “There is every reason to believe that a Sistema-like learning environment and Sistema-like program priorities can produce good results in almost any rewarding medium of group endeavor.”

But, they say, “there is something about music” — a sentence typical of the unsubstantiated, feel-good claims that fill this flabby, ardent book.

Anne Midgette is The Washington Post’s classical music critic.

Playing for Their Lives
The Global El Sistema Movement for Social Change Through Music

By Tricia Tunstall and Eric Booth

W.W. Norton. 408 pp. $28.95