I cut my dd’s floor music using GarageBand also. We have a Mac and the software came free with the Mac.
I found cutting floor music to be a lot more difficult than I thought it would be. The song dd chose had a lot of changes in key, so choosing the places to make the cuts so that the pieces spliced back together would sound like a smooth transition was actually very time consuming. The actual cutting wasn’t that difficult, but figuring out how to get all the pieces of the song that we wanted, plus making it the right length, and then making the spliced together parts sound smooth was difficult. I think that if she had chosen a different piece that didn’t have so many key changes, it would have been much easier.
I was really pleased with the outcome, but it just took a lot longer than I thought it would.