Bastianini was considered one of the finest Verdi and verismo voices of his day. He made his recital debut as a bass in Siena in 1945 and his stage debut later that year in Ravenna as Colline in Puccini's "La bohème." He later moved into the baritone range where he voice seemed better suited. His top notes thrilled audiences throughout his career for their ringing splendor.
He was a regular at La Scala between 1954-1963 and the Vienna State Opera between 1958-1964. In the United States, he performed regularly at Metropolitan Opera between 1954-1957 and at the Lyric Opera of Chicago between 1955-1958.
In 1962, he was diagnosed with a throat tumor. He struggled with the disease until his death in 1967 singing his final performance on December 1, 1965, at the Metropolitan Opera.