Granforte was one of the important baritones in Italian opera during the first half of the twentieth century, filling the gap left by Titta Ruffo, though he is neglected in some histories of the period. He had a warm, sonorous voice with a wide range, solid delivery, exceptional piano singing, and was acclaimed as a vocal and stage actor, as well.
Born in Italy (as Appollinari Granforte), Granforte showed a promising voice from an early age, and not having the money to study with a teacher, he taught himself to sing as a tenor while also preparing to support himself as a shoe maker. He made his debut as Arturo in Lucia di Lammermoor at the Legnano theater in 1905, where his voice was praised for its power, but also described as uncontrolled. Later that year he emigrated to Argentina, where he worked as a shoe maker until his voice was discovered by a wealthy opera lover, who financed his studies at the Buenos Aires conservatory, and he made his highly successful opera debut as a baritone as Germont in La Traviata in 1913 at the Politeama in Rosario, Argentina. He often returned to South America during the rest of his career, and sang at nearly every major house on that continent.
In 1916, he returned to Europe, appearing in various small opera houses. After a brief period of service in the Italian army during World War I, he made his Milan debut in a concert celebrating the armistice, conducted by Serafin. He continued to sing lead roles in smaller houses in Rome and Milan, eventually making his La Scala debut in 1922 as Amfortas in Parsifal. In 1923, he made his Verona debut in the world premiere of the now-forgotten, but then-successful, Misteri Gaudiosi by Cattozzo.
In 1924, Nellie Melba included him in her Australian touring company, and the next year, he began his long and fruitful relationship with HMV Records in London. In 1935, he created Menecrate in Mascagni's Nerone (he also recorded thinly veiled tributes to Mussolini and Fascism), and in 1938, he sang the Wanderer and Gunther in the first Italian-language performance of the Ring Cycle. He retired in 1943, his last performance being the world premiere of Liviabella's Antigone, but remained active. He joined the faculty at various conservatories in Europe, including the Milan Conservatory where he taught, among others, Raffaele Arie, and also briefly served as the director of the Prague National Theater.