Sullivan approached A.B. Mitford, who had been in a British envoy to Japan, regarding suitable music. However, his score remains resolutely Western, and indeed English, from a play on the song "A Fine Old English Gentleman" when Ko-Ko enters, to a madrigal, to even a little of Bach’s Fugue in G minor during "My object all sublime." Likewise, Gilbert's lyrics incorporate such traditional folk phrases as "derry down derry" and "tra-la-la." Only two pieces in The Mikado are in Japanese: the phrase "O ni! Bikkuri shakkuri to!" at the end of Act I (which Ian Bradley, editor of The Complete Annotated Gilbert and Sullivan, translates to "surprise, with a hiccup") and the "Miya sama" chorus, a genuine Japanese anthem.
Score aside, the original D'Oyly Carte production strove to be as authentically Japanese as possible. As shown in Topsy-Turvy, Gilbert did engage a woman from the Knightsbridge village to teach the female singers how to bow, giggle, and use their fans; and the entire cast was coached in the correct way to move in kimonos. Liberty of London, which had led the field in textiles during the Aesthetes' hunger for Japanese goods, supplied the theater with the fabrics for sets and costumes, even sending its own special envoy to Japan to make the selection. As a result, some the male performers wore genuine silk garments purchased in Japan, or expert reproductions of them (armor had been considered, but the real thing was found to be too heavy...and too small). The first Katisha wore a 200-year-old Japanese robe. Unfortunately, critics of the time did not appreciate such touches, complaining that the ladies looked like bolsters, that they were shaped too much like the men (remember, this was the era of corsets and bustles). However, the D'Oyly Carte company stood by such authenticity...and in fact continued to use some of the original costumes right up through the early 1980s.