The singer told MTV News the 'emotional' other-worldly experience prompted her to pen the track on the as-yet unnamed LP.
“There's a song on it that's inspired by a visit [from] my dead grandmother — like, I had really, really vivid dream about her and, um, she was giving me advice in this dream,' Welch said.
'And it was really emotional, and I woke up crying. And there's one song that's inspired by that experience.'
The record, which will be her second album, is in its final stages, although Welch admitted she isn’t quite ready to let go just yet.
'It's nearly finished, but, of course, that's the hardest part for me, because once it's finished, you have to share it with others,' she said.
'So, I've found myself obsessing over the way I've sung one little word, and wanting to go back and do it over again. I'm going to try and hold onto it as long as possible.'