Spotify released this feature to some users this summer: https://sea.mashable.com/entertainment/20715/spotifys-new-ka...

Though I have no idea how to get into this beta test.

This is a killer feature for me as I am trying to learn to sing.

There are some services online that use AI to split tracks into instruments and vocals that do hell of a job, but trying to combine them with written lyrics again is a pretty painful experience.