BOGOTA, Colombia (AP) — It has been praised the world over as a model for uplifting disadvantaged youth by connecting them with classical music.

But a new book about Venezuela's network of youth orchestras known as El Sistema, or The System, portrays it as a "model of tyranny" where brutal, marathon practice sessions mirror the apparently unlimited power and top-down style of its magnetic founder, Jose Antonio Abreu.

"El Sistema: Orchestrating Venezuela's Youth" is the first in-depth study to question the institution whose motto of social action through music has brought together aging, conservative devotees of classical music and Venezuela's socialist government, which has bankrolled El Sistema's expansion over the past 15 years.

United Kingdom-based musicologist and arts educator Geoffrey Baker said he embarked on his research after attending a heart-stirring 2007 concert at the Proms of London by the Simon Bolivar Youth Orchestra under the direction of El Sistema's best-known alum: Gustavo Dudamel, the 33-year-old wunderkind musical director of the Los Angeles Philharmonic.

The author of several books on Latin American music, Baker said his goal was to provide a rigorous study of the intellectual and organizational underpinnings of the musical marvel. But once in Venezuela he said he was overwhelmed by tales from current and former musicians of top-level corruption, favoritism and improper sexual relations between teachers and pupils.

"Like any big institution, problems exist but to suggest there is a widespread virus is absolutely false," Eduardo Mendez, El Sistema's executive director, said by telephone from Gothenburg, Sweden, as one of its ensembles wrapped up a European tour.

Abuses alleged in Baker's book run the gamut from shouting during rehearsals to reports of the trading of sexual favors and an orgy involving students and teachers at a retreat. Baker says he was unable to verify the claims and declined a request by The Associated Press to provide access to his confidential sources — ammunition for El Sistema's backers who reject his charges.

He also said he never intended to probe how pervasive abuse or disgruntlement is among the roughly 600,000 children studying in neighborhood music centers nationwide. Rather, he wanted to provide a counterweight to the hype he believes has skewed public opinion and fueled a global franchising of El Sistema's teaching model to 60 countries.

"Every story has two sides but so far only one side of El Sistema has been told," he said.

Much of the author's criticism focuses on Abreu, a former Cabinet minister in the government the late Hugo Chavez tried to overthrow in 1992 who founded El Sistema four decades ago. He has been collecting international praise and comparisons with Pope John Paul II and Nelson Mandela ever since.

But "El Maestro," as he's universally known, is as much feared as loved, says Baker. He's managed to adapt El Sistema to the new revolutionary times with an iron grip and political machinations that obscure any serious analysis of whether it is delivering on its social mission. The author also faults El Sistema for being out of step with a trend toward greater transparency and more innovative teaching techniques used in similarly influential European organizations.

Hanging out outside El Sistema's imposing concrete headquarters in Caracas, dozens of musicians belonging to the Simon Bolivar ensemble said they considered the book's claims outrageous. While acknowledging that the demands of the ensemble are weighty, they vigorously defended Abreu's vision, which they credit for building one of the few enduring institutions in Venezuela. None said they had witnessed cases of sexual abuse.

"It's like American football — to be on a team, you have to have extreme discipline. The coach doesn't say please and thank you," said upright bass player Abraham Maduro, who has been a member of the symphony system for 20 years.

While Baker's public reproach, first aired in a column in the Guardian newspaper, has fueled a firestorm, it's not clear what, if any, long-term impact it will have on El Sistema's reputation or its busy international touring schedule.

For now, El Sistema is showing no signs of slowing down. On Tuesday, Abreu appeared alongside President Nicolas Maduro on state TV celebrating the European tour and reviewing blueprints for the government-funded "Dudamel Hall" designed by L.A.-based architect Frank Gehry.

Arts educator Marshall Marcus witnessed up close El Sistema's birth as a young musician living in Venezuela during the late 1970s oil boom. In 2012, he established the Sistema Europe, a network of youth ensembles from 25 countries inspired by the Venezuelan model.

He acknowledged that the organization hasn't evolved as quickly as its track record for musical excellence. But he rejected Baker's lack of quantitative data and emotionally charged language comparing El Sistema to the mafia and slavery, saying it may only serve to incense critics who accuse Abreu and Dudamel of being too cozy with the government on which El Sistema's survival depends.

"It may be an autocracy but it's one that has allowed thousands of people to flourish," said Marcus. "If that's a tyranny, it sure doesn't feel like one."

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Hannah Dreier contributed to this report from Caracas, Venezuela.

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