Ulmar next was hired to play Yum-Yum in the D'Oyly Carte Opera Company's first American production of The Mikado, at the Fifth Avenue Theatre in New York, from 1885 to 1886, in a cast that included George Thorne (Ko-Ko), Courtice Pounds (Nanki-Poo), and Fred Billington (Pooh-Bah).[3] She joined a D'Oyly Carte touring company in England, singing Yum-Yum and Josephine for a few months, then Yum-Yum in the German company, before returning to America in the summer of 1886. D'Oyly Carte released her to play for an American manager, John Stetson, at the end of 1886, for whom she played in Carte-approved productions in New York of Princess Ida (in the title role) and The Mikado (as Yum-Yum) and then in Boston in the title role of Patience.[1]
In early 1887, Ulmar rejoined the D'Oyly Carte Opera Company in England, where she rehearsed the new Gilbert and Sullivan opera, Ruddygore (later renamed Ruddigore), played Rose Maybud in two matinee performances at the Savoy Theatre, and then returned to New York to play Rose in the American production. In May 1887, she returned to London to play Rose at the Savoy[4] and remained there to play the soprano roles in the 1888 London revivals of Pinafore, The Pirates of Penzance (Mabel) and The Mikado. The Times wrote, in 1887, that
"[S]he is born to the manner of the peculiar form of art invented by [Gilbert and Sullivan]. Her voice, although not very powerful, is quite capable of dealing with the composer's short-skirted airs, and the occasional dose of sentiment ... is quite within her reach.... Miss Ulmar’s style must be called a little prononcé. Her accents in the music, her treatment of the dialogue, and most of all, her by-play, are coloured a trifle more highly than is altogether compatible with the very subdued and refined tone of the general picture, which forms one of the most attractive features of the genre. At the same time she eschews any approach to vulgarity".[4]
Ulmar originated the leading soprano roles of Elsie Maynard in The Yeomen of the Guard (1888), and Gianetta in The Gondoliers (1889) before leaving D'Oyly Carte in 1890.[1]