It is not a sight – or a sound – that the well-heeled patrons of the Lucerne Easter Festival will forget in a hurry. However many times you have encountered Mahler’s Fifth Symphony, hearing it hurled out with the exuberant abandon of 150 Venezuelan teenagers – the superb players of the Simón BolÍvar Youth Orchestra – is a unique experience.

But seeing their infectiously charismatic conductor in action, the pint-sized but precociously gifted Gustavo Dudamel, is a pleasure all of its own. He jumps, he jigs, he dances, setting his shock of black curls flying in all directions. Best of all, he infuses the orchestra with a whip-cracking charge that binds them tightly from blistering start to pulverising finale. “But this energy comes from them,” the spent conductor protests weakly when we meet the next day for a restorative lunch. “They play with this . . . rraar!”

I don’t think it’s either an English or a Spanish expression, but it fits perfectly: not just for his orchestra, but for Dudamel himself, whose “rraar” factor has won him plaudits across the world. At just 26 years of age, he already has a record deal with DG in the bag: the next release, that Mahler Five with the Simón BolÍvar players, is out on Monday. He has conducted Don Giovanni at La Scala in Milan, and at a concert celebrating Pope Benedict XVI’s 80th birthday in Germany. In Europe, he will shortly begin his tenure as principal conductor of the Gothenburg Symphony Orchestra in Sweden; in America, he is the music director designate of the Los Angeles Philharmonic, where he was appointed after just two electric appearances with the orchestra. “The party sitting next to me put aside its just-opened giant bag of Cheetos and forgot about it until intermission,” reported the awestruck LA Times critic after his local debut: in California, it’s clearly high praise.

The Proms has hosted Dudamel once before, as an emergency substitute with the Gothenburg players in 2005. But this season he will be bringing the same players who so stunned the Swiss at Easter for their first outing in the UK (they also play at the Edinburgh Festival two days before). “For us to go to the Proms,” he beams, “is like a football team going to the World Cup. But the most important thing isn’t the Albert Hall, it’s the audience – the hall is amazing, but the audience is hot.”

Thankfully, the repertoire will match the occasion. “Shostakovich 10,” grins Dudamel, “also hot. And in the second half we will have Latin American pieces. It’s important to give the opportunity to make these composers universal.”

Plenty of youth orchestras achieve high standards. But even the best struggle to maintain the unanimity of ensemble that Dudamel’s band produced in Lucerne. But, again, he deflects the praise. “I think the secret of the group is that we have more than 15 years together,” he says. “I started to play in the orchestra when I was 11, with almost the same musicians, and our connection is almost like a family.”

It helps that Dudamel has been their chief conductor since he was 19. “It’s a great feeling when we play, because sometimes I don’t need to tell them anything. They follow me, and I follow them, like a river – it’s natural. Also, playing in this orchestra isn’t a job for them, it’s their life. They changed their life with the music and now they are changing the lives of the people listening.”

If you don’t know the story of the Simón BolÍvar Youth Orchestra, the glowing sentiment could sound a little phoney. But the truth is that Dudamel and this ensemble are the crowning glory of a musical education programme that leads the world in its scope and ambition: the National System of Youth and Children’s Orchestras of Venezuela (or simply Sistema or System), which brings musical tuition to some 250,000 impoverished Venezuelan children.

Through 200 youth orchestras (each is called a núcleo), this government-backed scheme has pulled children from the crime and drug-ridden barrios, of Venezuela’s cities with intensive practice and communal teaching, driving an ambition to eventually join the A team – the Simón BolÍvar Orchestra itself. The results have been so rewarding that a pilot scheme will shortly be launched in a deprived area of Stirling under the auspices of the Scottish Arts Council. “It’s the most special project in the classical music world,” explains Dudamel, “and this orchestra is just the top project of the System. Only when you go down the levels do you see that the energy of the orchestra comes from the bases of the System.”

And it’s all down to the frail man sitting unobtrusively in the midst of the Lucerne audience: the octogenarian José Antonio Abreu, a conductor, economist and politician, who somehow banged the right heads together 32 years ago to release the government funds and business sponsorship needed to finance the scheme, and has built it up since then. “He’s the real genius,” says Dudamel. “In the beginning it wasn’t easy for him, but he’s a very clear person with a very strong vision.” Somewhere along the line Abreu also found the time to coach the 16-year-old Dudamel how to wave a baton. “He’s my maestro, my teacher, he’s like my father.” Talking to Dudamel you soon realise that however far his already illustrious career takes him, he’s never going to forget the extended family that nurtured him, or the family in the orchestra that he now nurtures himself. “The relationship hasn’t changed, and never will,” he says simply. “They’re my brothers and sisters, and it’s important for me to be with them.”

Simón BolÍvar Youth Orchestra, Usher Hall, Edinburgh (www.eif.co.uk 0131-529 6000), Aug 17; Royal Albert Hall, SW7 (bbc.co.uk/proms/2007 ; www.royalalberthall.com 020-7589 8212), Aug 19. The new CD of Mahler’s Fifth Symphony is out on DG on Monday

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