Because @Robin_Lobel is suggesting that it can be done using the tools provided by Spectralayers here, I want to also point out that I was able to do it HERE on a very compressed video with all 5 lead singers being center in the front using Spectralayers pro 9. Knowing what I know now, if I had to go back in time and redo this unmixing I would rebalance the NOISE levels better between all the vocals a little more (because if you notice the first 2 vocals is deprived of acoustics and room NOISE whereas the 3rd vocal has most of the acoustics/room NOISE).