How to copy tracks?

I’m recording a choir using a karaoke track.
I use the karaoke as the base track and want to record multiple “takes” as additional tracks.
Problem is that each generation of recording is worse than the previous.
Is it possible to copy ONLY an additional track, without copying the base track and all other additional tracks?

Mac 10.10.5

Do you mean record, when you say copy?

You would have to choose the correct recording device in Audacity’s Device Toolbar. Don’t choose Soundflower or some tool that records computer playback.

What is the make and model number of the recording equipment? If it’s a mixer, you have to configure the mixer not to send the Audacity playback back to Audacity. Otherwise the playback will be re-recorded.

And if it is not obvious, wear headphones.