Or rather songs that create mashups inside your head when singing them to yourself when sitting in a train or so.... I have especially this one this year, the Danish entry Soldiers of love turns into the Irish one Sunlight in my head almost everytime. It doesn't mean they are even simliar but they just blend together nicely in my head.... Do you have similar experiences with other songs?
Let’s be soldiers of love, soldiers of love
We stay together, we’ll live forever