While emancipatory ethical social media campaigns play an imperative role for fostering relationship and facilitating peace, limited research has examined the motivational response from peace-promoting viral videos. This research scrutinizes the effects of a viral video titled “Peace Anthem”: a mash-up between Pakistani and Indian national anthems, performed by famous artists and broadcasted in the wake of Independence Day in India and Pakistan. We examine the effect of listening to the anthem medley on relationship harmony using a longitudinal study design (...) and contribute to the burgeoning body of knowledge on peace music and relational musicology fostering relationship harmony. Study 1, consisting of 1048 cases, determines the effects of the likeability of the “Peace Anthem” and education on relationship harmony, and it also examines the moderating role of education. Study 2 with 605 cases investigates the persistency of these effects over time. The results demonstrate significant relationships between the likeability of the “Peace Anthem” and education with relationship harmony, as well as validate the moderating role of education. Although these effects decrease over time, there are noteworthy changes that consequently call for the persistence of ethical social media campaigns for stimulating peace. We discuss the policy implications of these findings and conclude with study limitations and recommendations for further research. (shrink)