In the cartoon version of "Gulliver's Travels", (Not a Disney film) the two kingdoms have their own songs. When the prince of one country is going to marry the princess of the other country, each king says that his country's song should be played at the wedding.
One is Faithful
The other is Forever
When they are going to war over this, Gulliver suggests that the prince and princess each sing their song, interleaving the lines, which then becomes "Faithful Forever"...
and so on. It may have existed prior to the film....