During his visits to London, Pacchierotti mainly performed in operas by his friend Bertoni, now well known as a composer in the genre. In spite of the "many disadvantages of person" remarked on by Mount Edgcumbe, the singer continued to have ladies fall in love with him, notably Susanna Burney, daughter of the famous music historian Charles Burney, who described his singing as "divine". Known as "sweet Pacc" to Susanna and her sister Fanny (herself a well-known author and later Madame d'Arblay), he also earned their respect during the anti-Catholic Gordon Riots of June 1780 by refusing to remove his name from his door and, though an Italian Catholic, insisting on walking the streets openly while the mob yelled "No Popery!" As to further emotional entanglements, the notorious William Beckford wrote of one noblewoman, Lady Mary Duncan, that she was "more preciously fond" of the singer "than a she-bear of its suckling". Pacchierotti had met Beckford in 1780 at Lucca, during the young aristocrat's grand tour, and the following year he became involved in a performance marking that dissolute young nobleman's twenty-first birthday. This was of a cantata entitled "Il tributo", by a fellow castrato, Venanzio Rauzzini, long settled in England, and took place at Beckford's mansion Fonthill Splendens, near Bath. The third soloist was another castrato, Giusto Fernando Tenducci, a friend of Gainsborough. On 27 May 1784 Pacchierotti sang various arias by Handel at the centenary celebrations of the composer's birth held in the London Pantheon. His last visit to London in 1791 has become famous to posterity for his numerous performances of Haydn's cantata "Arianna a Naxos" to the composer's own piano accompaniment.