Leonardo Angelini worked with Opera Houses and Institutions such as Teatro dell’Opera di Roma, the Accademia Nazionale di Santa Cecilia, Opéra de Lausanne, Europäische Akademie für Musik und Darstellende Kunst Köln, singers such as Mirella Freni, Teresa Berganza, Renato Bruson, Fiorenza Cossotto, Antonietta Stella, June Anderson, Luciana Serra, Bernadette Manca di Nissa, Gianni Raimondi, Jaume Aragall, Louis Alva, conductors such as Maurizio Arena, Bruno Aprea, Donato Renzetti, Dario Lucantoni, instrumentalists such as Angelo Persichilli (flute), Georg Mönch and Franco Mezzena (violino), Giorgio Ravenna (violoncello), Massimo Giorgi (double bass).  From 2000 to 2011, he collaborated with the Ateneo Internazionale della Lirica in Sulmona and from 2004 to 2006 with Mirella Freni, Sergio Bertocchi, Lamberto Puggelli and Eva Wymola at the Centro Universale del Bel Canto in Vignola. Since 2018 he plays in regular collaboration with the Avant-scène Opéra Academy in Neuchâtel (Switzerland) and the Europa Musica, Europa InCanto and Ariadimusica Associations in operatic productions or lirical and instrumental Masterclasses.  He is the official accompanist of the prestigious International Singing Competitions “Maria Caniglia” in Sulmona, “Ottavio Ziino” in Rome, “Fausto Ricci” in Viterbo and “Jole De Maria” in Tivoli. He has recorded for the Vatican Radio and he has played for several years at the Opera Festival in Avenches, Verbier Festival and other cities of the Suisse Romande as Maestro concertatore at the piano for staged concerts of Aida, Traviata, Lucia of Lammermoor, Rigoletto and Don Giovanni.