What you might ask is a soul song, I will say that it is any sound that touches your heart, that you really feel. Often it will have lyrics that will speak to a particular problem or fit with your current mood.
The ancient emerald tablet speak of vibration or that all has a particular vibration. In the astral plane this is how we recognize each other by our vibration, by our soul song.
This song can change or evolve as we go through our lives. we go from nursery rhymes to Bach or Pink Floyd. For some they evolve to Jazz fusion or have a very eclectic sound scape. I would say the more genre of music you like indicates your past lives or for different aspects of your soul.
This gets me to the aspect I want to speak to it is Light Language or what in the christian way talking in tongues. These often if not always come in the form of a song even to the point of including a chorus. By this you might guess I listen to a lot of Light language and you would be correct.
This is how I came to this realisation when I went through my QHTT session the practitioner asked that I sing the song that the being that I was at that time sung as he/she was a singer in that society. I now find myself responding to Light Language with phrases of my own. Expression of my soul that I am now compelled to sing.
I hope that you will all embrace your soul song in whatever language it comes in set your soul free and sing your song.
Blessed Be Brother