Gatti studied singing in Florence with the tenor Vincenzo Guerrieri and later, at the Santa Cecilia Conservatory in Rome, with Maria Teresa Pediconi.
In 1971 he won the "Adriano Belli" experimental opera competition in Spoleto, and debuted at the Teatro Nuovo in the roles of Taddeo in Gioacchino Rossini's Italian in Algeri, Silvio in Pagliacci by Ruggero Leoncavallo and 'Sigismondo' in Gaetano Donizetti's Fat Thursday .
He has participated in some absolute "premieres": Jaufré Rudel and Trilby by Adolfo Gandino; The bear by Silvano Sardi; Four Odes of Horace by Bruno Nicolai; Question and answers by Virgilio Mortari; Perch'io by Roberto Gianotti; A night of joy by Arturo Annecchino; Glory by Franco Ferroni.
The show, directed by Giuseppe Patroni Griffi, also features Catherine Malfitano (Tosca), Ruggero Raimondi (Scarpia), Giacomo Prestia (Angelotti), Plácido Domingo (Cavaradossi) and the RAI Symphony Orchestra of Rome was conducted by Zubin Mehta; – La Traviata in Paris (2000) a live film broadcast in 125 countries on 5 continents.
In recent years, in addition to expanding his repertoire in the field of Italian comic opera of the '700, he ventured into the "musical" Caruso the Story of a Myth by Gianluca Terranova, 2002 and the musical comedy Victor Victoria by Blake Edwards', 2003 On 10 August 1997 he was awarded the title of honorary citizen of the Abruzzo town of Sante Marie.