I listened to Nana's Youtube song, D/L'd it and reduced the background hiss, run a HP filter to clean up the original recording. To use the recording on YouTube after that initial processing it would be best to gate her vocal track.

Nana is singing her song to an existing melody I am familiar with and so is my wife but neither of us have been able to recall the name of that song.

It is something similar to "99 bottles of Beer on the wall" but that is not exactly the melody.

If someone recognizes the melody she's singing, it will be a simple matter of getting a midi file of that song and using that chord progression to create a backing track.

Adding Nana to a new recording will require a bit of cut/pasting as well as time shifting and pitch correction.

I would suggest having Nana do the beginning of the song acapella into a fade out and fade in a new recording with another vocalist and backing track.

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