This research examines music encounters as a hitherto unexplored type of intergroup contact intervention. We tested the short- and mid-term effects of German–Polish music encounters that either took place in Germany or in Poland, respectively, on German's attitudes toward Poles. Ninety-nine German participants completed a questionnaire one week before the encounter (t0), directly thereafter (t1), and four weeks later (t2). The control group (N = 67) did not take part in any music encounter and completed the measures twice (t0 and t2). Results revealed that attitudes toward the Polish out-group improved sustainably, but only when the encounter took place in Poland. In contrast, for encounters realized in Germany, no attitude change occurred. Implications of these findings are discussed.