We investigated the influence of music during learning on the academic performance of undergraduate students, and more particularly the influence of affects induced by music. Altogether 249 students were involved in the study, divided into a control group and an experimental group. Both groups attended the same videotaped lecture, with the addition of classical music for the experimental group. Just after the lecture, both groups had to fill out a multiple choice questionnaire (MCQ) aimed to assess their learning during the lecture. The MCQ score of the experimental group was significantly higher than that of the control group. Affect just before the exam predicted significantly the MCQ-score, however music accounted for an additional part of variance. The effect of music on academic performance is not only about affects, and further research should investigate the underlying mechanisms resulting from a change in the perception of the learning environment. (Contains 3 tables.)