Afterwards he worked primarily in opera houses and concerts throughout the United States, although he did make numerous appearances in both Europe and South America as well.
Barioni was particularly associated with the operas of Giacomo Puccini and the roles of Turiddu in Pietro Mascagni's Cavalleria rusticana and Alfredo in Giuseppe Verdi's La traviata.
During his tenure at the Met, Barioni sang opposite some of the world's finest sopranos including Lucine Amara, Maria Callas, Mary Curtis Verna, Victoria de los Ángeles, Dorothy Kirsten, Zinka Milanov, Leonie Rysanek, Giulietta Simionato, Antonietta Stella, Anna Moffo and Renata Tebaldi among others.
He made his debut with the company on 20 February 1956 as Mario Cavaradossi in Tosca with Delia Rigal in the title role and George London as Scarpia.
Just two days later he sang his first Rodolfo in Puccini's La bohème opposite Licia Albanese, his most frequent leading lady at the Met, as Mimì.
During his second Met season, Barioni portrayed Pinkerton in Madame Butterfly and Alfredo in Verdi's La traviata in addition to singing Rodolfo and Cavaradossi, and Turridu.
Though for many years his career was mostly developed in the United States, he sang in Italy in different cities and theaters, and also in Brazil, Mexico, Argentina, Canada, Portugal, France, Germany and Ireland.
[1] His only commercial complete opera set was La rondine with Anna Moffo (RCA-1966); he appears briefly on Leontyne Price's fourth "Prima Donna" album.