Music files saved on harddrive through itunes, can these same files be managed in another music mgmt system?

My husband has downloaded a lot of music through itunes on our harddrive. I don't have an ipod, but, I have the same thing made by Sony. The music management system is called MusicMatch Jukebox. Musicmatch Jukebox is the software that manages all the music files and allows me to download to the Sony Digital player. Even though the songs downloaded on the harddrive through itunes are saved in our harddrive, it does not seem that I can Open the Music Match jukebox and add these songs into the musicmatch library. Does itunes restrict that these songs can be played in any other software other than itunes?

Music files saved on harddrive through itunes, can these same files be managed in another music mgmt system?
The songs downloaded in ITunes are in a format called AAC, which is an Apple format, and not the usual MP3. The other programs can't recognize the music files unless you convert them to MP3 or another format that they will recognize. You can search for programs to download that will convert music files, a lot of them are free. Try www.download.com.