I know how to remove the vocals, but somehow the harmonies remain. Is there any way to get rid of the harmonies?
They’re not harmonies necessarily. Vocal Removal – which only rarely works at all – is dependent on a whole raft of rules. One of the rules is that the tool will not remove stereo special effects, echo, reverb, or dimentional harmonies. These effects are frequently added to a vocal performance to make the singer sound fuller and more pleasing. They don’t come out when you remove the voice because they’re not in the middle of the sound field – the other rule. Everything in the middle goes, but conversely, everything not in the middle – like stereo effects, stays.
Another thing that kills vocal removal is aggressive MP3. Nothing like a little compression to mess up the sound field.