The present research examines adolescents’ appreciation of popular music and musicians against the background of the Optimal Distinctiveness Theory (ODT; Brewer, 1991). Within the framework of ODT, adolescents should favour music which maintains a balance between feelings of inclusion and distinctiveness (Abrams, 2009). Our research contributes to ODT by developing a diagnostic instrument, focusing on both the music and image, in order to measure objectively the degree of typicality. We hypothesized typicality is an essential factor which indicates an optimal level of distinctiveness of musical and personal style and thus predicts music appreciation in terms of a social identity. In the studies, adolescent participants evaluated different songs and images from actual popular music. Based on the methods of Classical Test Theory (CTT) and Item Response Theory (IRT), we identified 11 items to determine the typicality of music stimuli and 5 items to determine the typicality of musicians’ images. The results show that typicality is a reliable predictor of optimal distinctiveness and adolescent music appreciation (p < .01). Finally, we discuss additional experimental use of these scales and implications for research in the context of adolescents’ musical identities.