The Jesuits invent fusion

Paraguay in the 18th century was a melting-pot of Baroque and native music. Only now are its riches being appreciated

It has been a long time coming, but the new musicological buzz hails from the Jesuit Republic of Paraguay. The what? Well, this "country" was not the diminutive Paraguay of today: in 1700, it took in a vast swathe of South America including Brazil, Bolivia, Argentina and Peru, and its music was a three-way graft of African, Indian and Baroque elements, in one of world music's first kosher pieces of fusion.

If you've seen David Puttnam's cheesy melodrama The Mission, in which the virtuous Jeremy Irons converts the bad-hat Robert De Niro into a champion of the oppressed Indians, you will already know something of this story. Irons, you may remember, is a Jesuit priest who plays the oboe, until a village shaman angrily breaks it over his knee. The history behind this tale may now be largely forgotten, but for 200 years it provided inspiration to all believers in the communist ideal.

The Jesuits who set out to convert the tribes of South America in the late 16th century could not have been more different from their gold-digging compatriots. Altruistic men of peace, they were opposed to slavery, and established townships that were regulated societies, each with its school, hospital and church. "Everything was held in common," wrote Voltaire admiringly."Though neighbouring on Peru, they knew nothing of gold or silver."

No paternalism was more benign than that of these Jesuits, or more mourned when the Order was expelled from the continent in 1768, on the instructions of an angry Pope. Antonio Sepp, a Jesuit priest from the Tyrol, has left his account of a typical day's work: after private devotions, taking confessions, and saying Mass, "I instruct the children in the catechism, visit the sick, and, if it is not too late, prescribe medicines; and since hardly a day passes without somebody dying, I have daily burials. After the sick I visit the school. I also visit my musicians, singers, trumpets, hautboys etc. On certain days I instruct Indians in dancing. After that I go among the workmen. What spare time is left, I spend as I please, in making statues, composing musical pieces etc."

Music was the Jesuits' prime weapon in their ideological war. One priest reported that the Guarani people who filled the territory had the musical instincts of birds. "Give me an orchestra," wrote another, "and I shall conquer at once all these Indians for Christ." When the priests sang hymns from their canoes, the Guarani crept to the river banks to listen. In his "Spirit of Christianity", Chateaubriand later romanticised the scene thus: "Bows and arrows fell unheeded from the hands of the savages, and their souls received the first impression of a higher kind of existence and of the primitive delights of humanity."

The instruments the Jesuits found waiting for them included trumpets, flutes, and drums: with the aid of string instruments from Europe, they were able to import their whole musical culture, and to meld it with local pageantry. That process was recently explored in Travelling Instruments, Juan Carlos Jaramillo's illuminating series for the BBC World Service, but recently its leading latter-day proponents were to be found at Dartington Summer School.

Louis Berger – painter, doctor, composer – was one of the most creative Jesuits in 17th-century Paraguay, and in naming his ensemble after him, Ricardo Massun, the Argentine musicologist, is rendering belated dues. Yet Massun's discovery of his musical heritage was entirely accidental. "I was studying the cello in London, and one day my tutor showed me a Baroque score, which he said came from my country. I thought he was mad – I had no idea such music ever existed in my country. In Geneva, where I went to study next, I learnt more about it, and decided to form an ensemble to play it."

So here they are, with violins and cellos that look from a distance like ours, but are made of thicker wood, with a bleached, raw sound. The larger instruments' design is based on that of a wrecked 18th-century cello he found in a Bolivian museum; the violins have a more colourful provenance. Massun had heard of a young man making violins in a village in the jungle: since the only way to get there was by canoe, that was how he found him. "His workshop was a straw hut with a bare-earth floor, and when I asked who had taught him his craft, he said he'd learnt it from his uncle, who had in turn been taught by his grandfather. The method had come down in a direct line from the Jesuits themselves. It had not occurred to the young artisan that instruments could be made for sale to the outside world: his were employed in the local church, in combination with guitars. Massun commissioned several.

Since their bellies are thicker and heavier than those of European instruments, the sound lacks European brilliance; the cedar from which they are made is much harder than spruce. This has resulted in an oddity in the cellos: though their necks have four holes, they only have three strings. "We found that if we added a fourth string, either the top or the bottom didn't sound good. I've kept that empty fourth hole as a reminder to myself that my place is to learn from the Indians, and not to teach them retrospectively."

I notice other strange things in his band: cylindrical violins made from bamboo tubes. How come? "The Jesuits wouldn't allow their violins to be used for secular purposes, so the Indians had to devise their own." These instruments make a sweet but muted sound. "Okay, they've not got much volume," Massun agrees. "But imagine them in the silence of the night – that would be something else. None of the music composed for them remains, so I've had to compose my own."

But there's excitement in musicological circles about the music now being discovered in cathedrals all over Latin America. Massun's group– who will be heard today on Radio 3 at 1pm – perform some lovely stuff in the original Paraguayan dialects, from post-Monteverdi motets to pre-Handelian oratorios, plus a weirdly palindromic piece for two violins that sounds like Central European folk.

Meanwhile, the Dartington chorus, led by conductor Jeffrey Skidmore and his Ex Cathedra Choir, are working up some remarkable things. "It's mind-blowing to think what's still waiting out there in churches in the jungle," he says. "The British Library has so little on it, you'd almost think there was a conspiracy of silence. Listen to our Inca pavane." He beats a deep drum, while the choir and orchestra launch into a wonderfully rousing processional. As Dartington's director Gavin Henderson points out, there's a happy congruence between the ethos of the Jesuit townships and the the ethos of the original Dartington community. But with the bandwagon of Latin-American Baroque starting to roll, this is only a beginning.

The Louis Berger Ensamble play today on the Lunchtime Concert, BBC Radio 3, 1pm