Itunes transfer problems using Migration Assistant

I recently transferred everything on my old 2006 Macbook onto a new Macbook Pro using Migration Assistant. For some reason, not all of my music files came over into itunes the transfer. Some of the files were from CDs but others were purchased on itunes so I don't understand the issue. I can think of a long way to solve this problem by moving the music files myself using DropBox or a memory stick, but I'm hoping someone more knowledgeable can suggest a better way. Help!

Should not make any difference where the music came from. It's odd that they didn't transfer over. Could it be that you haven't authorized your new machine to play songs purchased while you were on the older machine?

Hmmm

Okay, maybe I don't know how to check that. I'll look into it. Good idea.