Italian composer and violinist. His fame rests above all on the composition of L'Arte del Violino, a set of twelve violin concertos issued together with 24 Capricci for solo violin (positioned in the first and last movements of each concerto). This collection made a big impact on the development of violin technique, above all in France, where from the early 19th century Locatelli's particular brand of virtuosity strongly influenced the teaching of the instrument. But though he was undoubtedly one of the founding fathers of modern virtuosity, he also left a corpus of music that - at least from his Op. 2 onwards - reflects the most advanced stylistic developments of his age.
Born to Filippo and Lucia Crocchi (or Trotta), he unquestionably had his early musical training in and around the organ-loft of the basilica of Santa Maria Maggiore, in Bergamo. He was probably taught by either Ludovico Ferronati or Carlo Antonio Marino, two of the city's most prominent musicians. By April 1710, when he was still 14, he was already a member of the instrumental ensemble active in the church. In January of the following year he was officially appointed third violin. In the same year (1711) he requested and obtained permission to go to Rome. It used to be thought that in Rome he became a pupil of Corelli - but this is a legitimate assumption only if we apply a particularly elastic meaning to the term 'school'. For Locatelli's violin skills were probably refined with the help of a distinguished virtuoso from the great Corelli's former entourage. A possible candidate is Giuseppe Valentini, who played alongside the young Locatelli at performances promoted by the noble Caetani family at Sermoneta in 1714. It is equally likely, however, that he turned to one of the eminent virtuosi working in the Ottoboni circle, such as Antonio Montanari or Domenico Ghilarducci. Between 1717 and 1723 we find that Locatelli, in the company of the finest performers of the day, was regularly called upon to play for Cardinale Pietro Ottoboni at the church of San Lorenzo in Damaso. From 1716 he took part, with a certain frequency, at the Congregazioni generali dei musici di S. Cecilia; his collaboration with this Roman corporation is repeatedly attested until 1722. It is not known with precision when he came into contact with Monsignor Camillo Cybo, major-domo to the Pope and dedicatee of the XII Concerti Grossi Opera I (1721), but he must have found himself under the protection of this noble prelate at a fairly early stage, perhaps even from the start of his membership of the Congregazione dei musici di S. Cecilia (1716). After February 1723, the date of his last attested performance at the household of Cardinal Ottoboni, Locatelli's biography becomes extremely poor in information. Though he might possibly be the otherwise unspecified 'bergamasco' who played at San Giacomo degli Spagnoli in Rome in July of the same year, one unassailable fact remains: he disappears from the Roman documents some time in 1723, at about the same time as the departure from the city of his protector, Monsignor Cybo.
The fact that Locatelli was appointed 'virtuoso da camera' in 1725 by Landgrave Philipp von Hessen-Darmstadt, the Habsburg governor of Mantua, is not in itself proof of an extended visit to his court, for not a trace of his passage has been found among the Mantuan documents. Nor, for that matter, do the Venetian archives make any mention of a visit to Venice, though the dedicatory letter to the patrician Girolamo Michiel Lini in his volume of concertos, the Arte del Violino (Op. 3), does imply that he stayed there some time between 1723 and 1727. On 26 June 1727 he is to be found north of the Alps, in Munich, at the court of the prince-elector Karl Albert, where his playing earned him 12 gold florins. The next year he was in Berlin, as is attested by a report made by the ambassador of Brunswick at the Prussian court, referring to a performance at the palace of Monbijou before Queen Sophia Dorothea. Tradition also has it that he arrived at the court of Frederick William I of Prussia from Dresden, in the retinue of Augustus the Strong (prince-elector of Saxony and king of Poland), and that two performances earned him the king's appreciation in the form of a 'sehr schwere goldene Dose mit Ducaten'. The difficulty of verifying this story is compounded with that of tracing Locatelli's association with Prince Augustus and the court of Dresden, for unfortunately all that survives to attest the link is the presence of a few compositions in the archive of the city's musical chapel. Locatelli next surfaces in 1728, when he signs a page - showing an Andante later published in his Sonata III for flute and continuo of his Op. 2 (1732) - in an album (Stammbuch) belonging to Hendrik van Uchelen, a merchant of Dutch origin who resided in Frankfurt am Main. In December of the same year he was in Kassel, where he was rewarded with 80 imperial thalers for 'services rendered' at the court of Landgrave Carl von Hessen-Kassel. It is also thanks to his contacts with the court of Kassel that his arrival in Amsterdam can be dated with fair approximation, for in a letter of December 1729 to Prince Maximilian von Hessen, he reports that he had been in Amsterdam for at least four months and expresses his intention to remain there over the whole winter.
Certainly, what attracted Locatelli to the Republic of the United Provinces - and, more specifically, to Amsterdam - was not so much the opportunity for concert activities as the strong Dutch tradition of music publishing, which could boast not only advanced technology but also an efficient network of distribution that guaranteed wide, international diffusion. When he arrived in Amsterdam, Locatelli resumed an association (begun back in 1721 over his Op. 1) with the publishing house of Roger-Le Cene, with which he arranged to bring out his orchestral works. The collections of chamber music (Opp. 2, 5 and 8), on the other hand, were published at his own expense and sold at his house. The careful planning and shrewd management he displayed in all his publishing ventures are confirmed by his application in 1731 to the States of Holland and Western Frisia for a 'privilege' to protect the printing of his works. The privilege was granted for 15 years and renewed in 1746.
As is borne out by his own testimony, as well as that of his contemporaries, Locatelli retired from public performance ('and he never will play any where but with Gentlemen'). Instead, regularly every Wednesday he held a concert at his own house for the benefit of what was probably a select circle of wealthy amateurs. The possessions found at his house on his death clearly show that the life he led during the 35 years spent in Amsterdam was a prosperous one. At his death his personal effects included not only a large collection of works of art but also a sizeable assortment of old books on various subjects and in various languages: of some there was more than one copy, suggesting that Locatelli possibly also engaged in the book trade - a plausible conjecture if we consider the number of affluent book-collectors in Holland at the time.