Is it possible to remove everything EXCEPT the lyrics from a song using audacity?
You can’t, because when a song is mixed down at the end of the production, it mixes all the different parts into two channels, or what you hear from the right and left speakers. You can’t separate the different parts after that. It would be like mixing different colours of paint through each other and then trying to take out one colour later. If a song so happened to be mixed in the way that the vocals were coming from the right speaker and all of the music from the left, then you could do it but it is not likely that any song would be like that the entire way through.
