Pakistan is celebrating its 70th Independence Day on 14 August, with historic rival India following one day later.
The two states share a tense relationship, primarily over the disputed territory of Kashmir, which sparked two wars between the sides.
Now a new song hopes to encourage tolerance - by uniting the countries' national anthems.
The "peace anthem" features singers from both Pakistan and India.
The pro-peace Facebook group Voice of Ram shared it online, and social media users from both countries have praised the song and the sentiment behind it.
The video begins with the words, "When we open our borders to art, peace comes along."
A series of artists then sing the Indian anthem Jana Gana Mana, and Pakistan's Pāk Sarzamīn - some from recording studios, others on location.
The footage closes with the words, "Let's stand together for peace".
An earlier video by Voice of Ram, posted on Facebook on 11 August, has already scored 468,000 views. It features an Indian a capella group, Voxchord, singing Pakistan's national anthem - which it calls "a song about faith, pride and grandeur, of power, progress and perfection".
Pakistan's Dawn newspaper described it as a "surprise offering", that is "quite a treat to listen to". On Twitter, listeners seemed moved by the gesture.
Filmmaker and activist Ram Subramanian, who heads Voice of Ram, told Indian site Catch News that he made the videos "because a lot of people are afraid to speak about peace, and it's an illogical fear".
An upsurge of violence in the region and along the Line of Control - the boundary dividing contested Kashmir- has seen casualties over the last year. Nationalists on both sides have accused people advocating peace of betraying their countries' dead soldiers, or even of committing sedition.
"To me, these videos mean a new beginning, another small step towards peace," Mr Subramanian said.
Writing on Facebook from India, Kalpesh Patel commented: "Hope this goes viral in Pakistan. Some of us Indians care for peace. The best "independence" day gift both countries can give each other."
Osama Farooqui from Karachi, Pakistan replied: "It has gone viral. Simply soulful and extremely peaceful listening to it. Love from Pakistan."