She made only a handful of opera appearances in Europe during her career, most notably singing in the English premiere of Riccardo Zandonai's Francesca da Rimini at Covent Garden in 1914.
[8] In the spring of 1914 Sharlow made her European debut in Paris as Cio-Cio-San in Puccini's Madama Butterfly with Henry Russell's opera company in that city.
[10] The Times stated in their review, "A special word of praise seems due to Miss Myrna Sharlow, who as Samaritana sang with an appealing freshness in her duet in the first act."
In September 1914 she made her New York City debut performing in one of the Century Opera Company's Sunday Night Concerts with Alexander Smallens accompanying her on the piano.
[12] From 1916-1920 she was committed to the Chicago Opera Association (COA) where she performed Aline in Xavier Leroux's Le chemineau,[13] Clotilde in Vincenzo Bellini's Norma[14] Ermyntrude in Pietro Mascagni's Isabeau,[15] Marguerite in Charles Gounod's Faust[16] Micaëla in Bizet's Carmen, Meg Page in Giuseppe Verdi's Falstaff, Sophie in Jules Massenet's Werther, and Urbain in Giacomo Meyerbeer's Les Huguenots.
[18] In 1919 Sharlow was heard at Ravinia Park with the Chicago Symphony Orchestra as all four soprano heroines in The Tales of Hoffmann and as Musetta to the Mimi of Florence Easton.
[25] In 1927 Sharlow toured North America with the San Carlo Grand Opera Company as Gounod's Marguerite and Puccini's Mimi.
[26] In 1928 she was committed to the Pennsylvania Grand Opera Company where she performed Maddalena di Coigny in Andrea Chénier and the title heroines in Aida and Tosca.
She also sang with the Columbia Grand Opera Company in Los Angeles and other cities on the West Coast of the United States during the late 1920s.
[28] Sharlow was committed to the Metropolitan Opera in the 1930-31 season, making her debut with the company on November 27, 1930, as Nedda in Ruggero Leoncavallo's Pagliacci with Giovanni Martinelli as Canio and Giuseppe De Luca as Tonio.