He had reconstructed the opera, the score of which had been lost in the fire. The new King's Theatre, Haymarket, opened for Italian opera under other direction in 1793. In the meantime, Mazzinghi had set music to Merry's comic opera, ‘The Magician no Conjuror,’ produced at Covent Garden on 2 February 1792. Other English operas by Mazzinghi were: ‘A Day in Turkey,’ 1791; ‘The Wife of Two Husbands,’ 1803; ‘The Exile,’ the Covent Garden company acting at the Opera House, 1808; ‘Free Knights,’ with the popular duet, ‘When a little farm we keep,’ 1810; and in collaboration with Reeve, who wrote the lighter airs, ‘Ramah Droog,’ 1798; ‘The Turnpike Gate,’ 1799; ‘Paul and Virginia,’ 1800; ‘The Blind Girl,’ 1801; and ‘Chains of the Heart,’ which gave much pleasure to George III, 1802. Mazzinghi's concertanti were played at the Professional Concerts (Pohl, Haydn in London), and his miscellaneous compositions were popular, especially those for the pianoforte. He taught the pianoforte to many influential pupils, among them the Princess of Wales, afterwards Queen Caroline. He was entrusted with the arrangement of the concerts at Carlton House, and of the Nobility concerts, established in 1791, and held on Sunday evenings at private houses. For fifty-six years Mazzinghi was a member of the Royal Society of Musicians. In about 1790 he entered into partnership with the firm of Goulding, D'Almaine, & Co., who published all his music after that date. Visiting Italy in 1834, Mazzinghi recovered the title of count. On his return to England he retired to Bath. He died on 15 January 1844, at Downside College, where he had been on a visit to his son. He was buried with some pomp in the vault of the Chelsea catholic church on 25 January. Besides the stage-pieces mentioned above, Mazzinghi published between seventy and eighty pianoforte sonatas; upwards of two hundred airs, &c., for pianoforte, and as many for harp and other instruments; thirty-five or more vocal trios, of which ‘The Wreath’ is still remembered; and a number of songs.