Conti was born in Arpino in 1714, possibly the son of the composer Nicola Conti.Dean. After studying in Naples with Domenico Gizzi, after whom he would later be nicknamed, he made his debut in Rome at an early age, around 1730. According to some modern encyclopedic sources, it took place in Leonardo Vinci's Artaserse, which premiered on 4 February at the Teatro delle Dame.Caruselli; Dean; Lisena. However, his name does not appear in the cast of the original libretto,Artaserse. Drama per Musica di Pietro Metastasio Romano tra gli Arcadi Artino Corasio. Da rappresentarsi nel Teatro detto delle Dame nel Carnevale dell'anno 1730, Rome, Zempel e de Mey, s.d. (1730), p. 8 (accessible for free online at IMSLP ). See also Kurt Sven Markstrom, The Operas of Leonardo Vinci, Napoletano, Hillsdale NY, Pendragon Press, 2007, p. 304, . and his theatrical debut ought probably to be dated instead in 1731, in revivals of Didone abbandonata and of the same Artaserse, both by Vinci.Fétis, p. 351; Villarosa, p. 54. A colourful anecdote relates how another overweening castrato star, Caffarelli, rode post-haste to Rome from Naples just to attend incognito his debut; and full of enthusiasm eventually yelled at him: "Bravo, bravissimo Gizziello, it’s Caffariello who's telling you!"Francesco Florimo, Cenno storico sulla Scuola musicale di Napoli, Naples, Rocco, 1869, II, p. 2042 (accessible for free online at Internet Archive). It is likely to be a legend. Whatever the case, at the beginning of 1732 he was urgently called upon to replace the castrato Nicolò Grimaldi (Nicolini), who suddenly died on 1 January during the rehearsals of Pergolesi's first opera La Salustia at the Teatro San Bartolomeo in Naples.Maria Grazia Sità, Salustia, in Piero Gelli and Filippo Poletti (eds), Dizionario dell'opera 2008, Milan, Baldini Castoldi Dalai, 2007, pp. 1176-1177, (the article is reproduced online at OperaManager.com ). Having become a member of the theatre's company, later that year he performed in new operas by Johann Adolf Hasse, Leonardo Leo and Francesco Mancini,Cf. catalogue of the performances by Conti in the website GFH (Handel for ever). and in revivals of Vinci's Catone in Utica and Artaserse.Conti's appearances in Catone in Utica and Artaserse are stated by Benedetto Croce, in I teatri di Napoli. Secolo XV-XVIII, Napoli, Pierro, 1891, p. 298 (accessible for free online at Internet Archive).
