Although composed by a Ukrainian in the late 1880s, the Thai royal anthem, “Sansoen Phra Barami,” occupies a central place in Thailand’s politics and culture. Contemporary vocal arrangements of the anthem show how performers use ornamentation to incorporate a Thai musical identity into an otherwise Western composition. More broadly, in Thai SATB choral repertoire, ornamentation influenced by the language’s linguistic tones serves as a strong marker of a Thai musical identity within a Western style. This paper will compare multiple performances of “Sansoen Phra Barami” and the classical song “Lao Duang Deuan,” investigating how choral performances incorporate ornamentation. Tanese-Itō (1988) and Swangviboonpong (2003) have outlined structural rules governing ornamentation in Thai classical singing, and List (1961), Ho (2006), and Tanprasert and Rockwell (2021), discuss treatment of falling and rising tones in Thai popular music’s text-setting practices. I will show how ornamentation in Thai choral music is different. For example, Tanese-Itō's formula for Thai classical singing, which is a highly ornamented style, predicts that a word with a falling tone will insert notes after and below the primary pitch. My analyses, however, show that in Thai contemporary choral music, the ornamentation will occur before and above the primary pitch for a falling tone. The cross-fertilization between Thai and Western musical styles creates a unique sound world with distinct ornamentation norms. By preserving traditional musical markers in a post-contact environment, Thai musicians create a new musical style, incorporating a Thai identity into traditionally Western contexts.