NMF works great for unsupervised audio source separation, e.g. [1]. See [2][3] for a good overview of the field.

[1] http://librosa.github.io/librosa/generated/librosa.decompose...

[2] https://hal.inria.fr/hal-01631185/document

[3] https://sci-hub.tw/10.1002/9781119279860.ch8