Recently, the number of music subjects in elementary curriculum has been decreased but the concern of English education has been increased. Therefore, this study aims to describe exact pronunciation of English choir songs when music teachers in the school teach English choir music. Teaching English choir music combines the merit of English class with that of music class. It requires vowel- oriented diction to unify the sound of chorus. Hence, consistent training of English syllable segmentation, Diphthong, Semi-vowel and the clear articulation of vowels are important for the harmonized sound in choir. English diction is different from an English conversation because it requires vowel-centered articulation as a result of time constraints of tune' s length in choir. Because teaching method and characteristic education are likely to change for elementary school students in global age, music educators in the schools need to have good understanding and precise knowledge of English vowels pronunciation for singing choir music. This study provides a teaching method to apply IPA to vowel articulation of Korean alphabets, and proposes a lesson plan to teach English vowels for the harmonized sound of choir class. I hope this instruction can help elementary teachers to educate English choir for elementary students in the future.