Help with Time machine/ freeing up space on my compter

Just my opinion, but that wouldn't be the best way to handle your music
It really isn't accessible in TMachine since it is designed just to back up and restore

It appears you want to delete it off your internal HD
But if you copy it over to the external and delete it from the internal, you still haven't backed it up
You have just transferred it

You need a comprehensive backup strategy

Edit: No, TM won't delete it from the back up... but it will only be available back in time, not in the most recent backups

Woof, Woof - Dawg

 

I would buy another External hard drive and move all your music over to that and then tell iTunes to look in that HardDisk for all your music.

As mentioned Time Machine will not really work this way.

 

Buying an external drive and moving the music there and pointing it to iTunes is the best solution. If you delete music off the main drive (assuming TM is set to overwrite older backups when TM disk gets full eventually), TM will delete the backed up music (but it should ask if you set it up that way).

Also, consider archiving the music using DVDs.