For the orchestra, likewise, it’s an awkward adjustment. The role of social worker to America’s underclass does not fit easily with the stringent demands of making music at an international level. The Baltimore Symphony depends on wealthy donors to pay its wages. It raises $1.3 million a year to fund OrchKids, but money is getting hard to come by in a city whose centre has been vacated by the middle classes. Baltimore musicians are about the worst-paid in any major US orchestra, on around $70,000 a year. The Peabody Conservatory, America’s oldest, has to market itself in China to maintain student numbers. Music is fighting here for its own survival.

I am dumbstruck with humility at the dedication of the OrchKids tutors I meet — the school secretary who stays on voluntarily after hours and seems to know every child and parent, the singing teacher who exudes rhythm and charisma in equal measure — and still I cannot ignore the glaring gulf between the gravity of the social crisis and the limitations of the musical remedy. What I have seen in Baltimore deepens my nagging disquiet at the universal application of the Sistema model.

El Sistema was designed by José Antonio Abreu, a Venezuelan economist and politician, to rescue barrios urchins from drugs and guns by teaching them a negotiable set of musical skills. It achieved stunning results under one of the world’s most violent and least competent regimes, yielding a flurry of fine soloists and conductors and several Simón Bolívar-branded orchestras that play with a confraternal passion which is as distinctive as it is inimitable. Watching a Bolívar orchestra and chorus of former street kids accompany La Bohème at La Scala, Milan, last summer was, for me, a clinching vindication of the social experiment, at least in respect of its original home base.

Abroad, El Sistema has been embraced as a model for social regeneration in Europe and the US, attracting such high-profile advocates as Leonard Bernstein’s daughter Jamie, the cellist Julian Lloyd Webber and the violinist Nicola Benedetti. However, except in Los Angeles, where Abreu’s brilliant protégé Gustavo Dudamel has driven a compelling YOLA programme among mostly Hispanic youth, El Sistema has failed to demonstrate — on Scottish sink estates and Italian summer camps, for instance — that symphonic music can repair social deprivation and communal disintegration.

Music is music, make of it what you will. Music can enhance life’s achievements and console us in our losses, but it cannot repair the holes at the heart of society. Few, if any, OrchKids will win a $45,000 scholarship at Peabody or a $70,000 job in the Baltimore Symphony. Life is not equipped with happy endings as default. And while my admiration for OrchKids is unqualified, I am increasingly concerned at the assumption it helps to project that music is a panacea for social woes.

There is no proof that classical music does more for unprivileged kids than after-hours football, pottery painting or software design. It may not even be more fun for the children, especially for the significant minority who are tone-deaf or manually undexterous.

El Sistema has fostered a seductive illusion that music is an all-purpose solution. But music has its limits and we need to accept them. It cannot cure cancer, relieve poverty or revive a dying city.

The Baltimore Symphony will celebrate its centenary next year — if Baltimore itself shows the will to survive.