How To Move Entire iTunes Library to External Hard Drive

[ghsDUDE]

So I've been having issues with my iPhone 6 syncing to iTunes. I realized it may have to do with my iTunes Media being on the external hard drive and everything else on my iMac. This was the guide I used a few years ago to do this.

http://support.apple.com/en-us/HT201562

After looking through some other guides, users recommended putting everything in one place on the external hard drive. (See the third post).

https://discussions.apple.com/thread/4594518

My question - would putting everything in one place be better? If so, how can I now get the playlist/album art/etc on the external hard drive?

Thanks