Riccardi began his career shortly after the Second World War as a lyric tenor at major and middle opera houses in his native Italy. Since debuting as an opera singer in 1947 he gave at the Teatro San Carlo in Naples in the role of Pinkerton in Madama Butterfly. Until the early 1950s Riccardi sang in his ancestral role. However, he then completed a professional and repertoire change and took over in the further course of his career almost exclusively comprimario and character games. He sang numerous medium, smaller, often smallest roles. He was considered one of the leading comprimario tenors of the post-war period.
In 1954 he made his debut at La Scala of Milano, where he performed regularly in comprimario roles until the end of the 1960s. At the Scala he was Monostatos in The Magic Flute (in Italian), Goro in Madama Butterfly, Minister Pang in Turandot, servant Bardolfo in Falstaff, Abbé in Adriana Lecouvreur and Monk Missail in Boris Godunov. In 1978 he appeared for the last time at the Scala.