He was born in Rome, where his father, Felice Trapassi, a native of Assisi, had taken service in the Corsican regiment of the papal forces. Felice married a Bolognese woman, Francesca Galasti, and established himself in business as a grocer in the Via dei Cappellari. Two sons and two daughters were the fruit of this marriage. The eldest son, Leopoldo, played an important part in the poet's life.
Pietro, while still a child, is said to have attracted crowds by reciting impromptu verses on a given subject. On one such occasion 1709, two men of distinction stopped to listen: Giovanni Vincenzo Gravina, famous for legal and literary erudition as well as his dictatorship of the Arcadian Academy, and Lorenzini, a critic of some note. Gravina was attracted by the boy's poetic talent and personal charm, and made Pietro his protégé; in the course of a few weeks he adopted him. Felice Trapassi was glad enough to give his son the chance of a good education and introduction into society.
Gravina hellenized the boy's name Trapassi into Metastasio, and intended his adopted son to be a jurist like himself. He therefore made the boy learn Latin and begin the study of Law. At the same time he cultivated his literary gifts, and displayed the youthful prodigy both at his own house and in the Roman coteries. Metastasio soon found himself competing with the most celebrated improvvisatori of his time in Italy. Days spent in severe studies and evenings devoted to the task of improvising eighty stanzas at a single session were fast ruining Pietro's health and straining his poetic faculty. At this juncture Gravina had to journey into Calabria on business. He took Metastasio with him, exhibited him in the literary circles of Naples, and then placed him under the care of his kinsman Gregorio Caroprese at Scaléa. In country air and the quiet of the southern seashore Metastasio's health revived. Gravina decided that he should never improvise again, but should be reserved for nobler efforts, when, having completed his education, he might enter into competition with the greatest poets.
Metastasio responded to his patron's wishes. At the age of twelve he translated the Iliad into octave stanzas; and two years later he composed a tragedy in the manner of Seneca on a subject from Trissino's Italia liberata - Gravina's favourite epic. It was called Giustino. Gravina had it printed in 1713; but the play is lifeless; and forty-two years later Metastasio told his publisher, Calsabigi, that he would willingly suppress it. Caroprese died in 1714, leaving Gravina his heir; and in 1718 Gravina also died. Metastasio inherited a fortune of 15,000 scudi. At a meeting of the Arcadian Academy, he recited an elegy on his patron, and then settled down to enjoy his wealth.
Metastasio was now twenty. During the last four years he had worn the costume of abbé, having taken the minor orders without which it was then useless to expect advancement in Rome. His romantic history, personal beauty, charming manners and distinguished talents made him fashionable. Within two years he had spent his money and increased his reputation. He now decided to apply himself seriously to the work of his profession. In Naples, he entered the office of an eminent lawyer named Castagnola, who exercised severe control over his time and energies.
While slaving at the law, Metastasio in 1721 composed an Epithalamium, and probably also his first musical serenade, Endimione, on the occasion of the marriage of his patroness the Princess Pinelli di Sangro to the Marchese Belmonte Pignatelli. In 1722, the birthday of the empress had to be celebrated with more than ordinary honours, and the viceroy applied to Metastasio to compose a serenata for the occasion. He accepted this invitation, but it was arranged that his authorship should be kept secret. Under these conditions Metastasio produced Gli orti esperidi. Set to music by Nicola Porpora, and sung by Porpora's pupil, the castrato Farinelli, making a spectacular debut, it won the most extraordinary applause. The great Roman prima donna, Marianna Bulgarelli, called 'La Romanina' from her birthplace, who had played Venus in this drama, spared no pains until she had discovered its author.
La Romanina persuaded the poet to give up the law, and promised to secure for him fame and independence if he would devote his talents to the musical drama. In La Romanina's house Metastasio became acquainted with the greatest composers of the day - including Porpora, from whom he took lessons in music; with Hasse, Pergolese, Alessandro Scarlatti, Vinci, Leo, Durante, and Marcello, all of whom were destined in the future to set his plays to melody. Here too he studied the art of singing, and learned to appreciate the style of such men as Farinelli. Gifted with extraordinary facility in composition, and with a true poetic feeling, he found no difficulty in producing plays which, while beautiful in themselves, judged merely as works of literary art, became masterpieces as soon as their words were set to music, and rendered by the singers of the greatest school of vocal art the world has ever seen. Reading Metastasio in the study, it is impossible to do him justice. But the conventionality of all his plots, the absurdities of many of his situations, the violence he does to history in the persons of some leading characters, his "damnable iteration" of the theme of love in all its phases, are explained and justified by music.
Metastasio lived with La Romanina and her husband in Rome. Moved by an affection half maternal half romantic, and by a true artist's admiration for so rare a talent, she adopted him more passionately even than Gravina had done. She took the whole Trapassi family - father, mother, brother, sisters - into her own house. She fostered the poet's genius and pampered his caprices. Under her influence he wrote in rapid succession the Didone abbandonata, Catone in Utica, Ezio, Alessandro nell' Indie, Semiramide riconosciuta, Siroe and Artaserse. These dramas were set to music by the chief composers of the day, and performed in the chief towns of Italy.
But meanwhile La Romanina was growing older; she had ceased to sing in public; and the poet felt himself more and more dependent in an irksome sense upon her kindness. He gained 300 scudi for each opera; this pay, though good, was precarious, and he longed for some fixed engagement. In September 1729 he received the offer of the post of court poet to the theatre at Vienna, with a stipend of 3000 florins. This he at once accepted. La Romanina unselfishly sped him on his way to glory. She took the charge of his family in Rome, and he set off for Austria.
In the early summer of 1730 Metastasio settled at Vienna in the house of a Spanish Neapolitan, Niccolo Martinez, where he resided until his death. This date marks a new period in his artistic activity. Between the years 1730 and 1740 his finest dramas, Adriano, Demetrio, Issipile, Demofoonte, Olimpiade, Clemenza di Tito, Achille in Sciro, Temistocle and Attilio Regolo, were produced for the imperial theatre. Some of them had to be composed for special occasions, with almost incredible rapidity - the Achille in eighteen days, the Ipermestra in nine. Poet, composer, musical copyist and singer did their work together in frantic haste. Metastasio understood the technique of his peculiar art in its minutest details. The experience gained at Naples and Rome, quickened by the excitement of his new career at Vienna, enabled him almost instinctively, and as it were by inspiration, to hit the exact mark aimed at in the opera.
At Vienna Metastasio met with no marked social success. His plebeian birth excluded him from aristocratic circles. To make up in some measure for this comparative failure, he enjoyed the intimacy of the Countess Althann, sister-in-law of his old patroness the Princess Belmonte Pignatelli. She had lost her husband, and had some while occupied the post of chief favourite to the emperor. Metastasio's liaison with her became so close that it was believed they had been privately married.
La Romanina had tired of his absence, and asked Metastasio to get her an engagement at the court theatre. He was ashamed of her and tired of her, and wrote dissuading her from the projected visit. The tone of his letters alarmed and irritated her. She seems to have set out from Rome, but died suddenly upon the road. All we know is that she left him her fortune after her husband's life interest in it had expired, and that Metastasio, overwhelmed with grief and remorse, immediately renounced the legacy. This disinterested act plunged the Bulgarelli-Metastasio household at Rome into confusion. La Romanina's widower married again. Leopoldo Trapassi, and his father and sister, were thrown upon their own resources.
As time advanced, the life which Metastasio led at Vienna, together with the climate, told on his health and spirits. From about the year 1745 onward he wrote little, though the cantatas which belong to this period, and the canzonetta Ecco quel fiero istante, which he sent to his friend Farinelli, rank among the most popular of his productions. It was clear, as Vernon Lee has phrased it, that "what ailed him was mental and moral ennui". In 1755 the Countess Althann died, and Metastasio was reduced to the society which gathered round him in the bourgeois house of the Martinez. He sank rapidly into the habits of old age; and, though he lived till the year 1782, he was very inactive. He bequeathed his whole fortune of some 130,000 florins to the five children of his friend Martinez. He had survived all his Italian relatives.
During the forty years in which Metastasio overlived his originality and creative powers his fame went on increasing. In his library he counted as many as forty editions of his own works. They had been translated into French, English, German, Spanish, even into modern Greek. They had been set to music over and over again by every composer of distinction, each opera receiving this honour in turn from several of the most illustrious men of Europe. They had been sung by the best virtuosi in every capital, and there was not a literary academy of note which had not conferred on him the honour of membership. Strangers of distinction passing through Vienna made a point of paying their respects to the old poet at his lodgings in the Kohlmarkt Gasse.
But his poetry was intended for a certain style of music - for the music of omnipotent vocalists, of thaumaturgical soprani. With the changes effected in the musical drama by Gluck and Mozart, with the development of orchestration and the rapid growth of the German manner, a new type of libretto came into demand. Metastasio's plays fell into undeserved neglect, together with the music to which he had linked them. Farinelli, whom he styled "twin-brother", was the true exponent of his poetry; and, with the abolition of the class of singers to which Farinelli belonged, Metastasio's music suffered eclipse. It was indeed a just symbolic instinct which made the poet dub this unique soprano his twin brother.
The musical drama for which Metastasio composed, and in working for which his genius found its proper sphere, has so wholly passed away that it is now difficult to assign his true place as a poet in Italian literary history. His inspiration was essentially emotional and lyrical. The chief dramatic situations are expressed by lyrics for two or three voices, embodying the several contending passions of the agents brought into conflict by the circumstances of the plot. The total result is not pure literature, but literature supremely fit for musical effect. Language in Metastasio's hands is exquisitely pure and limpid.
Of the Italian poets, he professed a special admiration for Tasso and for Giambattista Marini. But he avoided the conceits of the latter, and was no master over the refined richness of the former's diction. His own style reveals the improviser's facility. Of the Latin poets he studied Ovid with the greatest pleasure, and from this predilection some of his own literary qualities may be derived. For sweetness of versification, for limpidity of diction, for delicacy of sentiment, for romantic situations exquisitely rendered in the simplest style, and for a certain delicate beauty of imagery sometimes soaring to ideal sublimity, he deserves to be appreciated so long as the Italian language lasts.
There are numerous editions of Metastasio's works. That by Calsabigi (Paris, 1755, 5 vols. 8vo) published under his own superintendence, was the poet's favourite. The posthumous works were printed at Vienna, 1795. Metastasio's life was written by Aluigi (Assisi, 1783) by Charles Burney (London, 1796), and by others.