The present research seeks to develop a scale that can measure attitudes toward different musical expressions representative of different social groups, such as the Andean and Afro-Peruvian groups. The participants were 312 individuals between 18 and 83 years of age (M = 32.42, SD = 14.97), and the majority had no professional musical knowledge. First, Exploratory Factor Analysis was performed using the Unweighted Least Squares as the extraction method and using Oblimin rotation for the Andean and Afro-Peruvian musical genres. An identical factorial structure with two dimensions was found for both musical genres, obtaining optimal reliability according to Cronbach’s alpha coefficients. This similarity was verified by performing an invariance analysis, obtaining evidence that the proposed scale can be used regardless of the musical genre. Furthermore, correlation analyses were performed between the dimensions of the attitudes scale and variables such as stereotypes (toward the Andean and Afro-Peruvian social groups) and conservative ideology; the results provided evidence of discriminant validity. Finally, comparisons were made between musicians and non-musicians using the same dimensions of the attitude scale as evidence for criterion validity. The results are discussed based on scale’s optimal psychometric functioning, as well as its implications at the level of intergroup dynamics.