The "Mozart effect" refers to claims that people perform better on tests of spatial abilities after listening to music composed by Mozart. We examined whether the Mozart effect is a consequence of between-condition differences in arousal and mood. Participants completed a test of spatial abilities after listening to music or sitting in silence. The music was a Mozart sonata (a pleasant and energetic piece) for some participants and an Albinoni adagio (a slow, sad piece) for others. We also measured enjoyment, arousal, and mood. Performance on the spatial task was better following the music than the silence condition, but only for participants who heard Mozart. The two music selections also induced differential responding on the enjoyment, arousal, and mood measures. Moreover, when such differences were held constant by statistical means, the Mozart effect disappeared. These findings provide compelling evidence that the Mozart effect is an artifact of arousal and mood.