Jommelli’s musical training began under Canon Muzzillo, director of the cathedral choir at Aversa. In 1725 he went to the Conservatorio S Onofrio in Naples, where he studied with Prota and Feo; he transferred to the Conservatorio Pietà dei Turchini in 1728, where his teachers included Nicola Fago. He was also influenced by the composers active in Naples during his student years, notably Hasse and Leo. Later, to Schubart, he admitted his debt to both Hasse and Graun. His public career began with two comic operas for Naples, L’errore amorosa in spring 1737 and Odoardo in winter 1738. The success of his first serious opera, Ricimero re di Goti, at Rome in 1740 brought him to the attention of a wealthy and influential patron, Cardinal Henry Benedict, Duke of York.
An early exposure to Hasse’s obbligato recitative must have impressed the young Jommelli with the capacity of motivic orchestral writing to create an intensified emotional effect at particularly dramatic moments. Speaking of Jommelli’s obbligato recitative for Ricimero, Charles de Brosses declared that the force of the declamation, the variety of the harmony and the sublimity of the accompaniment created a sense of drama greater than the best French recitative and the most beautiful of Italian melody.
For the production of his setting of Metastasio’s Ezio in 1741, Jommelli moved to Bologna, where he met and had lessons with Giovanni Battista (‘Padre’) Martini, establishing a lifelong friendship (nine letters from Jommelli to Martini are in I-Bc). He was elected a member of the Accademia Filarmonica. Later that year he composed his first opera for Venice, Merope. Its first and second acts are linked with an unusual scene including chorus, obbligato recitative, ballet and pantomime, depicting war games, foreshadowing in startling fashion the French-inspired operas to come in the latter half of the century. In the next few years he wrote operas for Bologna, Venice, Turin, Ferrara and Padua, as well as two oratorios which were widely performed, Isacco figura del Redentore and La Betulia liberata.
In 1743 or 1745 Jommelli received, on Hasse’s recommendation, his first permanent position as musical director of the Ospedale degli Incurabili, one of Venice’s conservatories for girls. Early biographers place this appointment in 1743 but all of his compositions for the conservatory date from 1745 or after. For the women who sang in the church services, he composed a group of sacred works, among them two oratorios, a Kyrie–Gloria mass, settings of psalms and several solo motets. He also wrote a Te Deum for mixed voices. These works show a great variety in the types of movements, use of keys, sequences of choruses, arias and ensembles. The most important sacred composition of this period is the psalm Laudate pueri in B for two women’s choruses, soloists and two string orchestras. In addition to this output of sacred music, Jommelli maintained his creativity in the operatic sphere.
The basic characteristics of his mature style were already emerging: the incursion of declamatory elements in the aria, audacious harmonic effects, abundant modulations, chromaticism, and the exploration of orchestral resources such as the use of the second violin as an independent textural element, the occasional independent viola parts, the abundant dynamic indications and the development of the crescendo effect, which reached Mannheim from Italy through Jommelli’s Italian sinfonias, in which Johann Stamitz first heard the innovations since credited to him. Symphonic construction, without repeat signs and with a contrasting second theme in the dominant key, contrasting sections for pairs of instruments, sharp dynamic contrasts and crescendos can all be found in Jommelli’s opera sinfonias of the 1740s. The basic units of compositions, at the level of motif and phrase in Jommelli’s sinfonias, doubled (as Wolf has observed) in the 1740s: 2 + 2 becomes 4 + 4. The same process in vocal music led to a doubling in the length of the ordinary aria during the decade. Equally significant, Jommelli increasingly wrote arias in which the internal structure and function are clearly differentiated, using techniques associated with instrumental sonata procedures. Many of his arias of the 1740s have first themes, transitions, second and closing themes, clearly delineated by changes in texture, dynamics and orchestration. His interest in formal clarity was most pronounced during this decade, during which he was writing the most ‘modern-sounding’ music of anyone (Terradellas being a close second and Galuppi joining them around 1745); he also stands out for his interest and skill in the details of expression.
Jommelli left Venice at the end of 1746 or the beginning of 1747, because on 28 January 1747 he produced in Rome his first version of Didone abbandonata. In addition to operas for Rome, Jommelli fulfilled commissions for Naples and Parma. In 1748 Jommelli wrote L’amore in maschera, his first comic opera for ten years. His few intermezzos followed within a few years. L’uccellatrice was written for Venice and performed there in May 1750. A reworked version, Il parataio, was presented by the Italian buffo troupe during its controversial appearance in Paris in 1753. Thus Jommelli, along with Pergolesi and others, contributed fodder to the Querelle des Bouffons and to the clamour for more italianate elements in French opera voiced by the Encyclopedists Rousseau, Grimm and Diderot.
In the early 1750s Jommelli’s work gravitated towards sacred music, beginning with the oratorio La passione di Gesù Cristo, composed in Rome in 1749. The composer dedicated this work to Cardinal Heinrich Benedict, Duke of York, who had been his patron for many years. This gained him entrance to influential papal circles, where he met Cardinal Albani. In the first days of April 1749 the prefect of music in the Vatican, Monsignor Passionei, commissioned Jommelli and another Neapolitan composer, David Perez, to write a Miserere as a demonstration of their capabilities. Backed by Cardinal Albani and Passionei, Jommelli was then elected maestro coadiutore of S Pietro with a decree issued on 20 April. The decree asserted that he must be in Rome for the beginning of the Holy Jubilee Year of 1750 and follow indispensably the year-round service in the basilica.
Meanwhile, equally important to his career was a commission Albani secured for him from Vienna in 1749. Here he composed Achille in Sciro and a second version of Didone abbandonata. Metastasio, then court poet at Vienna, reported that Jommelli’s Achille far exceeded expectations. He believed Jommelli to be unrivalled in his ability to seize the heart of the listener with his delicate and sensitive melody. The early Viennese symphonists, Dittersdorf and Wagenseil, later acknowledged Jommelli’s influence upon the formation of their symphonic style (see Hell, 1971).
Jommelli returned from Vienna to Rome somewhat late, and there he found that the Congregazione di S Cecilia was trying to prevent him from assuming his duties as maestro di cappella at S Pietro. The pope himself had to declare that Jommelli was his virtuoso in order to exempt him from the examination of the Congregazione. It was only on 14 June 1750, the day of Corpus Christi, that Jommelli appeared for the first time at S Pietro as maestro di cappella. Thus began a period of creativity during which the output of sacred music reached for the first – and only – time in his life a level at least comparable to that of his operatic output. For about three and a half years Jommelli composed a considerable number of liturgical pieces as regular requirements for the Cappella Giulia. Besides contributions to the proprium of the Mass (sequences, graduals and offertories), most of them were destined for the musical services of the Offices, particularly in the Vespers. The compositions are mostly written in the stile nuovo as, for example, the imposing psalm Dixit Dominus (1751) in F for solo voices, two four-part choirs and string orchestra, which contains a quartet for four virtuoso solo sopranos as well as an impressive sextet illustrating Jommelli’s highly developed art of antiphonal ensemble movements. On the other hand, his fugues of up to eight parts show a noteworthy contrapuntal skill, and also of interest is the hymn Aurea luce (1750) for solo voices, double choir and figured bass. Contemporary reports attest that a total of 11 vocal groups – subdivisions of the available choirs – participated and were stationed throughout S Pietro, even in the cupola. In addition to these works, there exist several compositions for Holy Week, written in stile antico, the most outstanding of which is the complete cycle of 27 responsories for Holy Week.
By 1751 Jommelli had returned to a demanding schedule of opera composition. During the next four years he fulfilled commissions for Rome, Spoleto, Milan, Piacenza and Turin. Significant and permanent changes in Jommelli’s approach to opera had taken place during his Roman sojourn (1747–55).
In Vienna Jommelli found a demand for chorus and ensemble scenes long out of vogue in Italy. Achille in Sciro is one of Metastasio’s few librettos requiring a chorus. Although there are no ensembles in Jommelli’s operas for Vienna, Galuppi’s Artaserse performed during the previous carnival has an important ensemble, and there are a number of them in the pasticcios, for example the quartet in Merope. On his return to Italy in the early 1750s, Jommelli began incorporating ensembles and substantial final choruses into his operas. Mainly homophonic with solo and antiphonal sections, these pieces have points of imitation and independent part-writing even in the traditionally homophonic final chorus.
In pursuit of the dramatic, Jommelli cut both recitative and aria from Metastasian librettos, increasing the number of obbligato recitatives. The most powerful obbligato solo scenes were written for Dido’s death at the end of Didone abbandonata and for Regolus’s farewell to Rome at the close of Attilio Regolo. Burney described the latter as producing such an uncommon effect during a production in London (1754) that it was encored, the only instance within his memory when a scene of recitative had inspired such a response.