Moving audio from Final Cut Pro to GarageBand

I am a music teacher and new to this program. I would like to create a Virtual Choir. I understand from the video side how to get multiple videos in one frame, but is there a way to move the audio to GarageBand so that I can edit it and better sync it, then export a master audio file back? I saw that you can detach the audio from individual movies, but can't seem to move it into a DAW. Any help would be greatly appreciated!

Thanks in advance.

Why not edit and sync your audio inside of FCPX? All the tools you need are there. If you have Logic Pro X you can send your audio from FCPX to it, but it's not a perfect workflow. Again, most everything you need is in FCPX.