Are you able to isolate the vocals? If so, invert the phase, and then subtract the result from the original recording.
As for isolating the vocals, I’d wager that it is panned to the center, so if you manage to isolate anything with a perfect 50/50 left/right split, what you’ll have should be the vocals. Use that as a subtractor, and the end result should be most of the music. Yes, the music probably also has something panned to the center, which you would lose in this process, but maybe it’s good enough for someone to recognize the track.
Are you able to isolate the vocals? If so, invert the phase, and then subtract the result from the original recording.
As for isolating the vocals, I’d wager that it is panned to the center, so if you manage to isolate anything with a perfect 50/50 left/right split, what you’ll have should be the vocals. Use that as a subtractor, and the end result should be most of the music. Yes, the music probably also has something panned to the center, which you would lose in this process, but maybe it’s good enough for someone to recognize the track.
The phase inversion trick can’t be used with mono tracks, nor can other tricks that use the stereo field.