The present study investigates the effects of choir music on secretory immunoglobulin A (S-IgA), cortisol, and emotional states in members of a mixed amateur choir. Subjects participated in two conditions during two rehearsals 1 week apart, namely singing versus listening to choral music. Saliva samples and subjective measures of affect were taken both before each session and 60 min later. Repeated measure analyses of variance were conducted for positive and negative affect scores, S-IgA, and cortisol. Results indicate several significant effects. In particular, singing leads to increases in positive affect and S-IgA, while negative affect is reduced. Listening to choral music leads to an increase in negative affect, and decreases in levels of cortisol. These results suggest that choir singing positively influences both emotional affect and immune competence. The observation that subjective and physiological responses differed between listening and singing conditions invites further investigation of task factors.