iTunes content Transfer

[djm151]

My son and I have shared the same iTunes account for several years but his A/V stuff is on one computer and mine is on another.Now, he wants his own iTunes account, which is understandable. How can we transfer his music (Purchased and downloaded from CD's) to a new iTunes account. Apple says it can't be done, but if the music is saved to an external Hard Drive, or DVD's wouldn't one be able to import that music to a new iTunes account?