Involuntary musical imagery—music popping into your head that is not present in the environment—is a common experience, but relatively little is known about individual differences in involuntary musical imagery. The present research examined the Involuntary Musical Imagery Scale (IMIS), a promising new measure that assesses the frequency and qualities of involuntary musical imagery, in relation to broad personality traits and schizotypy. A sample of 182 young adults completed the IMIS along with measures of personality (the HEXACO-100; NEO-PI-3 Openness) and schizotypy (the brief Wisconsin Schizotypy Scales). Openness to experience, neuroticism (HEXACO Emotionality), and positive schizotypy traits were correlated with the frequency of involuntary musical imagery as well as with many of its facets. Overall, the IMIS seems promising for exploring individual differences in involuntary experiences of musical imagery.