Travelling by way of Innsbruck, Roveredo, and Verona, and meeting everywhere with a most enthusiastic reception, Mozart, with his father, reached Mantua on January 10, 1770. The Philharmonic Society of the city gave a concert on the 16th of the same month, which was in reality a public exhibition of Wolfgang's powers. The programme has fortunately been preserved, and we learn from it that in addition to two of his symphonies, of which he probably directed the performance, he played at first sight a concerto for the harpsichord that was placed before him. He also played at sight a sonata, introducing variations of his own, and afterwards transposed the whole piece into another key. More remarkable still was his improvisation. He extemporized a sonata and a regularly constructed fugue on themes given him at the moment. He also sang and composed extempore a song on words not previously seen, accompanying himself on the harpsichord.
The travellers' next stay was at Milan, where they found a warm friend in Count Firmian, the Governor-General of Lombardy, who interested himself with such success on behalf of Wolfgang that the latter received a commission to compose an opera for the next season, after giving proof of his powers for serious opera by setting three songs from the poems of Metastasio.
Passing through Parma, Bologna (where they made the acquaintance of the celebrated theorist Padre Martini) and Florence, the Mozarts arrived in Rome during Holy Week. It was on this occasion that Wolfgang performed the feat, so often recorded, of writing down from memory Allegri's Miserere after having heard it sung, in the Sistine Chapel. After a visit for a month to Naples, they returned to Rome, where the Pope invested Wolfgang with the order of the Golden Spur.
Revisiting Bologna on his return journey, the lad received the honour of being elected a member of the Philharmonic Society of that city. As a test-piece he composed an antiphon in four parts, Quœrite primum regnum Dei, in the strict contrapuntal style of the old Church music. His father, writing home an account of the affair, says:
"The princeps academiæ and the two censors, who are all old kapellmeisters, put before him in the presence of all the members an antiphon from the Antiphonarium, which he was to set in four parts in an adjoining room, to which he was conducted by the beadle and locked in. When he had finished it, it was examined by the censors and all the kapellmeisters and composers, who then voted upon it with black and white balls. As all the balls were white, he was called in, and all clapped on his entry, and applauded him after the princeps academiæ had announced his reception in the name of the society. He returned thanks, and all was over. I was meantime shut up in the library on the other side of the hall. All were astonished that he had done it so quickly, as many take three hours over an antiphon of three lines. You should know, though, that it is no easy task, for there are many things forbidden in this kind of composition, as he had been previously told. He finished it in exactly half an hour."
While staying at Bologna, Mozart received from Milan the libretto of the opera which he was to write. According to his custom, he wrote the recitatives first, deferring the composition of the airs till he had made acquaintance with the singers, in order that he might suit them the better with their parts. On October 18, Wolfgang and his father returned to Milan, and the boy at once set to work diligently to finish the opera, which was to be produced at Christmas. The subject of the work was Mitridate, Re di Ponto, the libretto being written by a poet of Turin named Cigna-Santi. All the airs were written after consultation with those who were to sing them.
As at Vienna, so at Milan: jealous musicians intrigued to hinder the success of the work, but their efforts were in vain. The principal singers and the members of the orchestra were delighted with the music, and on December 26 it was produced, with so brilliant a result as to silence the detractors. The opera was repeated twenty times to always crowded houses, and with ever-increasing success. At the end of March, 1771, Wolfgang was again in Salzburg.
Two important musical works were the result of the success of Mitridate. The impresario at Milan engaged Wolfgang to write an opera for the season of 1773, while the Empress Maria Theresa commissioned him to compose a theatrical serenata for the marriage of the Archduke Ferdinand, which was to take place at Milan in October, 1771. The work was Ascanio in Alba, which was produced on October 17 with very complete success. The celebrated Hasse, a friend of the Mozarts, and an honourable man, who had always sided with Wolfgang against his detractors, had written an opera, Ruggiero, for the same festivities. Leopold Mozart writes home: "I am sorry that Wolfgang's serenata has so eclipsed Hasse's opera that it is indescribable." Hasse himself was generous enough to acknowledge his defeat, and to say: "This youth will make us all to be forgotten," a prophecy that has been amply fulfilled.
During the greater part of the year 1772 Wolfgang was at home, composing music of almost every kind. An event which took place at this time had an important influence on his future. This was the death of the Archbishop of Salzburg, and the election in his place of Hieronymus, Count of Colloredo, a haughty and surly man, who cared nothing whatever for music. For his installation Mozart composed the one-act allegorical opera, Il Sogno di Scipione—not one of his stronger works. In November of the same year we find him once more in Milan, busy with the new opera that he had been engaged to write. This was Lucio Silla, the words of which were written by a local poet. It was produced on December 26, and repeated more than twenty times to crowded houses. The opera contains some beautiful numbers; but Mozart had not yet emancipated himself from tradition, and it is not till some years later that his dramatic genius shows itself in its full strength. After the production of Lucio Silla, Leopold Mozart, with his son, remained some time in Italy, in the hope of the latter obtaining an appointment in the Court of the Grand Duke Leopold at Florence. This hope was not realized, and in March they returned to Salzburg.