[Zubersoft]

At the moment, I think your only option is to either add each track to the same song and then switch between them using the audio player, or create a copy of the song and add the different audio track to each copy. In the future I will be adding the song versioning feature where you could have two versions of the same song with a different audio file attached to each. On the library screen, you could then select which version you want to load.

Mike