Interesting this should come up now. I just bought Izotope RX7 which has a built in 'Music Rebalancer' and, according to their PR, this uses machine learning t

Interesting this should come up now. I just bought Izotope RX7 which has a built in 'Music Rebalancer' and, according to their PR, this uses machine learning techniques. I've been playing around with it this week in spare time and have been quite impressed with how well it works on quite disparate sources from my music collection. It's extremely useful when you want to transcribe details from instrumental tracks that are hard to discern past the vocals in the overall mix. It seems to work less well on material that's been crushed in the mix/mastering, and material that has a lot of upper-mid content competing with the vocals. On clean, open material, it works remarkably well.