I am moving from my iMac to MBP. Because of less internal storage I have copied my 1.5 TB iTunes Media folder to three 2TB external drives as a safety precaution. Now I have read that I should have copied the iTunes folder instead of iTunes Media. Will this make a difference? Also, in the iTunes folder I can see various (7) "Previous iTunes Libraries", going back to may 2013. Is it safe to delete these? Thanks.