The purpose of this mixed-methods study was to examine the relationships between music achievement y musical self-esteem, and music aptitude of subjects (N = 20) in a songwriting course for undergraduate non-music majors. Criterion measures used were Advanced Measures of Musical Audiation, Self-Esteem of Musical Ability, and ratings of subjects’ original compositions. Two judges rated the compositions using a researcher-designed rating scale. Journals kept by students throughout the semester were coded and analyzed for the following themes related to musical self-esteem: Personal Desire/Interest, Support/Recognition from Others, and Perceived Music Ability. Significant relationships (p < .05) were found between all criterion measures. With encouragement from teachers and opportunities for social music-making more students may develop a greater interest in music, achieve at higher levels, and be more likely to continue music instruction. Replication with larger samples, samples of different age levels, and in other geographic areas is recommended.