The music historian Charles Burney spent several weeks in Vienna in 1772. One of his most cherished ambitions was to meet the court poet Pietro Metastasio, whose librettos, set to music hundreds of times, had helped to shape the music of his age. But once in the presence of the great dramatist, Burney found his attention distracted by the entrance of a young woman, “who was received by the whole company with great respect. She was well dressed, and had a very elegant appearance.” This was Marianna Martines, whose family had lived with Metastasio for about forty years and whose education he had supervised. She had developed quickly into a fine singer, keyboard player, and composer, and was now, at the age of twenty-eight, at the height of her creative powers.

Burney had heard about Martines already. Giuseppe Antonio Taruffi, an official at the Nunciature, the papal embassy in Vienna, had aroused his curiosity by praising her exceptional musical abilities and accomplishments:

After the high encomiums bestowed by the Abate Taruffi on the talents of this young lady, I was very desirous of hearing and conversing with her; and Metastasio was soon so obliging as to propose her sitting down to the harpsichord, which she immediately did, in a graceful manner, without the parade of diffidence, or the trouble of importunity. Her performance indeed surpassed all that I had been made to expect. She sung two airs of her own composition, to words of Metastasio, which she accompanied on the harpsichord, in a very judicious and masterly manner; and, in playing the ritornels, I could discover a very brilliant finger.

Martines's singing left Burney at a loss for words:

To say that her voice was naturally well-toned and sweet, that she had an excellent shake, a perfect intonation, a facility of executing the most rapid and difficult passages, and a touching expression, would be to say no more than I have already said, and with truth, of others; but here I want words that would still encrease the significance and energy of these expressions.