There have been plenty of Baroque anniversaries to enjoy this year: Monteverdi’s Vespers are 400, Alessandro Scarlatti is 350, and it’s 300 years since the birth of Thomas Arne and Wilhelm Friedemann Bach. But of all this year’s honourees no one has proved quite so troublesome to commemorate as the Neapolitan composer Giovanni Battista Pergolesi. Recent research suggests that what we know of his life from his first biographer, the Marquis of Villarosa, is a garbled mixture of half truths, misinformation and pure invention. And of the 148 pieces published in the first complete edition of Pergolesi’s works, only about 30 are now thought to be genuine. So, who and what are we really celebrating?

Pergolesi’s main problem – and our greatest loss – is that his creative life spanned just six years. Dead and buried by the age of 26, he didn’t have time to write very much, and just when everyone realised what a good thing he was… it was too late. But, contrary to expectations, dying actually proved to be something of a boost to his career. ‘The instant [Pergolesi’s] death was known,’ wrote the 18th-century music historian Charles Burney, ‘all Italy manifested an eager desire to hear and possess his productions’.

Demand rapidly outstripped supply and ‘Pergolesi’ soon became a popular brand, allowing unscrupulous publishers to market even the most anonymous music under his name. Indeed, if the output of 18th-century presses and copyists were taken at face value, then Pergolesi was far busier in the decade or so after his death than he was in six years before. Three centuries on, sorting the wheat from the chaff is still a tortuous business. The New Grove Dictionary of Music valiantly tries to grade the music attributed to him in descending order of reliability, ending up with the categories ‘Doubtful’, ‘Extremely Doubtful’ and the outright ‘Spurious’.

Once it had gathered momentum, the Pergolesi industry didn’t stop at the fabrication of his music and biography. The public wanted to know what this talented young man looked like. The truth – in as much as we can gauge it three centuries later – was not pretty. The only authentic image of the composer we have, sketched by Pier-Leone Ghezzi in around 1734, shows him with one leg shorter than the other, a snub nose and thick protruding lips. But in the hands of 18th-century artists and engravers he was transformed into the perfect, angelic young man with ethereal features and flowing locks.

When all these myths and claims of spuriousness are stripped away, Pergolesi’s reputation rests on surprisingly narrow shoulders. Scholars have authenticated just eight stage works, a sacred drama, an oratorio and six chamber cantatas. For the church there are a couple of masses, various works for Vespers plus the well-known Stabat mater. Though an accomplished violinist, Pergolesi seems to have had little interest in writing for the instrument: the 100 or so pieces which bear his name can now be whittled down to just five genuine sonatas and a single concerto.

In the 18th century, Pergolesi’s fame was kept alive by two similarly scored but vividly contrasted works: a comedy, La serva padrona; and a tragedy, the Stabat mater. After his death they became two of the most frequently performed and talked-about works of the century. But La serva padrona (The Maid as Mistress) started life humbly as an intermezzo – a popular form of interval entertainment in Neapolitan opera houses. Performed by specialist troupes of actor-singers, their plots had nothing to do with the main opera but instead revelled in the lighter aspects of love. The comedy generally revolved around two characters, one of whom got the better of the other. In La serva padrona it is the scheming young serving-girl Serpina (‘little snake’) who outwits the old buffoon Uberto and tricks him into marrying her.

La serva padrona originally offered comic relief from Pergolesi’s Il prigioniero superbo (1733), but this 40-minute practical joke rapidly outshone its parent and was soon tickling audiences on its own. But it didn’t just amuse. Arriving in Paris in 1752 it caused one of the greatest operatic uproars of all time. Performed by a home-grown Italian cast between the acts of Lully’s Acis et Galatée (1686), it led to a two-year pamphlet war about the respective merits of traditional French opera versus the lighter, comic style which was all the rage in Italy. Later known as ‘La Querelle des Bouffons’ (the Quarrel of the Comedians), it saw such serious philosophers as Denis Diderot and Jean-Jacques Rousseau take up their pens in the Italian cause; Rousseau even composed his own intermezzo, Le Devin du Village, in imitation. Pergolesi’s comic masterpiece, with its rapid-fire dialogue and tuneful pattering melodies, continued to wield influence as late as Mozart’s Così fan tutte (1790).

Mozart and Pergolesi spent their final weeks wrestling with a similar demon. But unlike Mozart, Pergolesi actually won his final struggle. Just days before his death from tuberculosis in March 1736 he put the finishing touches to his setting of the Stabat mater – the Virgin Mary’s personal Requiem for her crucified son. The 13th-century text is an emotional retelling of the Passion story in which the poet – probably a Franciscan monk – imagines the sufferings of the Virgin Mary at the foot of the cross and asks to share in her grief. Pergolesi’s setting was probably commissioned in 1734 by a fraternity of Neapolitan noblemen who gathered on the Friday before Palm Sunday each year to hear the Stabat mater they had commissioned from Alessandro Scarlatti. But by the 1730s they wanted something a little more fashionable, though for the same modest forces – soprano and alto soloists plus strings.

What Pergolesi produced was a carefully balanced sequence of five arias and seven duets entirely different in style from the grand manner of his masses and psalm settings. Instead, the Stabat mater drew on the new lighter galant style he was championing in the theatre which made its impact through sheer force of melody. Applying this style to church music was cutting-edge stuff, and for some listeners it was too much. The Italian theorist Padre Martini, writing in 1774, thought the Stabat mater was too lightweight and much too close in style to Pergolesi’s own La serva padrona to convey ‘pious, devout and contrite sentiments’. But others, particularly in France, found his depiction of the sorrowing Virgin deeply moving, even to the point of tears. Rousseau, again, was a supporter. For him the opening of the Stabat mater was ‘the most perfect and touching duet to come from the pen of any composer’.

Padre Martini was right, though: Pergolesi’s style was loaded with operatic overtones. But what reached out to listeners was its simple, bittersweet lyricism – Pergolesi may not have been able to portray the Virgin Mary with the immediacy of an opera character, but he was certainly able to make her seem less medieval and more modern, less of a mystery and more of a mother. Anchored in earthly rhythms, tuneful melodies and uncomplicated textures, Pergolesi’s Virgin is approachable and unaffected. Where traditional church music of the time achieved its effect through solemnity and grandeur, Pergolesi’s Stabat mater is designed to appeal to our emotions, to court our sympathy for a grieving mother, which surely accounts for its undiminished power and enduring appeal today.

Though the sacred credentials of the Stabat mater were still being debated by a few well into the 19th century, music lovers of all classes voted with their feet. Louis XVI attended annual performances in the splendour of the Royal Chapel at Versailles, and from 1753 the French public flocked to hear it at the most prestigious concert series in Paris – the Concert Spirituel – where not even a Revolution could silence Pergolesi for long. And once the Stabat mater was finally published in London in 1749, there was no stopping it. Before the first centenary of Pergolesi’s birth it had become one of the most frequently reprinted works of the century.

In England it was widely performed by professionals and amateurs alike and, just as with any other popular vocal work, favourite arias and duets were often extracted and sung on their own. By the 1760s the music was so well loved that it was adapted to Alexander Pope’s celebrated ode ‘A Dying Christian to his Soul’. It got a new text in Germany too, and at the same time Pergolesi received a posthumous composition lesson from no less a teacher than Bach. He reshaped and simplified the vocal lines to suit the words of Psalm 51 (‘Tilge, Höchster’), demonstrated how a new viola part could enrich the texture, and achieved a more optimistic conclusion, changing the order of a couple of movements and doubling the length of the final ‘Amen’.

The tinkering didn’t stop here. Just like Messiah, the Stabat mater changed shape and scoring to suit the fashions of each new age. By the late 19th century the addition of a full symphony orchestra and massed choirs shocked even Wagner. Today the pendulum has swung the other way as the historically-informed, one-to-a-part approach has gained favour and swept Pergolesi to even greater popularity. With around 50 recordings currently available, the Stabat mater ranks alongside Vivaldi’s Gloria and Bach’s Magnificat in the catalogue. But its very popularity has diverted our attention from the rest of Pergolesi’s rich, if tiny, legacy.

After 300 years it’s really time we got to know Pergolesi’s two exquisite settings of the Salve regina for soprano and strings, his large-scale Vespers psalms and ‘San Emidio’ Mass, as well as the amusing intermezzo Livietta e Tracollo – all of which are available in excellent recordings. Not so his operas, containing some of his finest music, which still await first-rate modern recordings – something which needs sorting out well before the next anniversary in 2036.

Simon Heighes