The influence of musical experience on children's perception of culturally familiar (native) and culturally unfamiliar (nonnative) musical scales was studied. Western musician and nonmusician 10- to 13-year olds were tested in detection of mistunings in a melody based on either the Western major, Western minor, or Javanese pelog scales. In the Javanese scale context, the performance of the musicians was not different from that of the nonmusicians, and neither group detected mistunings in this context significantly better than chance. The child musicians' performance in the Western contexts, however, was better than in the Javanese context and also was better than that of the child nonmusicians. In contrast, the child nonmusicians' performance in the Western contexts was significantly better than chance, but these children did not have significantly greater success at detecting mistunings in the Western than Javanese contexts. These findings suggest that informal musical acculturation results in somewhat better perception of native than nonnative scales by 10-13 years of age but that formal musical experience can facilitate the acculturation process. These results are compared with other published data on infants and adults tested with the same stimuli.