Yes, unless you know how to move them. Get yourself a USB flash drive, or a firewire drive. I have a 250GB firewire that moved 20GB of my music to my newer iBook within 15 minutes. It is very convenient because if I had started to rip (convert) the songs from each music CD it would have taken weeks.
In the Mac, your music folder usually sits in
- Root:Users:YourName:Music:iTunes Music
Good luck transfering!