He established himself as an opera conductor in Parma in the early 1880s, conducting several works which starred his brother, the tenor Italo Campanini.

[1] In 1883 Campanini was invited to New York City to join the staff of the newly created Metropolitan Opera for its inaugural season as an assistant conductor.

[4] In 1884 he returned to Italy, and that year he was appointed as the music director and conductor of a series of orchestral concerts at the Turin World's Fair of 1884, one of which featured Arturo Toscanini as the cello soloist.

At that theatre he conducted the world premieres of Augusto Machado's Mario Wetter (1898) and Alfredo Keil's Serrana (1899) (considered the best Portuguese opera) with his wife Eva in the leading roles.

[1][4] He introduced numerous works in these languages to the United States, including Hérodiade, Le jongleur de Notre-Dame, Grisélidis, Cendrillon, Cléopâtre, I gioielli della Madonna, Monna Vanna, Jules Massenet's Sapho, Isabeau, Conchita, Cristoforo Colombo, Déjanire, Sylvio Lazzari's Le Sauteriot, Vittorio Gnecchi's Cassandra, Jean Nouguès's Quo Vadis, Jan Blockx's Princesse d'Auberge, Frédéric Alfred d'Erlanger's Noël, Raoul Gunsbourg's Le Vieil Aigle, and Attilio Parelli's I dispettosi amanti.

He conducted the United States premieres of Karl Goldmark's Das Heimchem am Herd and Wilhelm Kienzl's Der Kuhreigen.

[1] These included the United States premieres of Jules Massenet's Thaïs (1907), Charpentier’s Louise (1908), and Claude Debussy’s Pelléas et Mélisande (1908).

[8] After a year of planning, the company gave its inaugural performance at the Auditorium Theatre on November 3, 1910 with Campanini conducting Giuseppe Verdi's Aida with Polish soprano Jeanne Korolewicz-Wayda in the title role, Amedeo Bassi as Radames, Eleonora de Cisneros as Amneris, Berardo Berardi as the King of Egypt, Mario Sammarco as Amonasro, and Nazzareno De Angelis as Ramfis.

Under that name, Campanini conducted the world premiere of Victor Herbert's Natoma at the Metropolitan Opera House in Philadelphia in 1911 with Mary Garden in the title part.

[10] That same year the company also appeared at the Metropolitan Opera House in New York City, presenting the United States premiere of Wolf-Ferrari's Il segreto di Susanna on March 14, 1911 with Carolina White in the title role.

[1] When the CGOC was disbanded in 1915 and the Chicago Opera Association (COA) was founded in its place, he was appointed general manager and principal conductor of that company as well, a post he remained in until his death in 1919.