Using an experimental approach, this study examined the relative effectiveness of varying the use of songs (lyrics and music) on vocabulary acquisition, language usage, and meaning for adult ESL students in the People's Republic of China. While the use of songs is generally enthusiastically endorsed by ESL teachers, few empirical studies have formally assessed music's actual effectiveness on language learning. Results of this study showed that varying the degree of use of songs produced differential English language achievement. Specifically, the subjects who were exposed to the most music obtained higher achievement and attitude posttest scores immediately following treatment, as well as on the delayed post-test three weeks following treatment. Given the equivocal results found in previous research, and the fact that previous studies did not examine music's effectiveness for Chinese ESL students, this study makes a contribution by systematically examining the efficacy of song use in the ESL classroom with Chinese students.