Q: New iTunes Account Transfer?

Items purchased with an account remain permanently tied to that account.  You can use items from other accounts on a computer but you need to make sure the computer is authorized to that account.  I also strongly recommend you make backup copies of items from the old account so you do not need to frequently re-download purchased media.  To do so you need to change the AppleID associated with the computer which you can only do once every 90 days.

iTunes Store: Associating a device or computer to your Apple ID - http://support.apple.com/kb/HT4627 -  In connection with, "When you turn on iTunes Match or Automatic Downloads, or when you download past purchases on an iOS device or computer, that device or computer becomes associated with your Apple ID." "Your Apple ID can have up to 10 devices and computers (combined) associated with it. Each computer must also be authorized using the same Apple ID. Once a device or computer is associated with your Apple ID, you cannot associate that device or computer with another Apple ID for 90 days." - Additional instructions for "Removing an associated device or computer from an Apple ID"

The only way to do this would be to sign on the Apple ID used to purchase the items originally on the iTunes account on your new computer, and Authorize the computer for that Apple ID. Then you could download any purchases made by that Apple ID into the iTunes Library on that new computer.

You would also want to Authorize the computer for your new Apple ID as well, and sign that on once you had downoladed the apps and music for the other Apple ID.

Just remember, that going forward, you would need to know the password for that other ID because when updating Apps you are often asked for a password, and it would be asking for the password for the Apple ID that purchased the apps to start with.

Cheers,

GB

wait so does that mean that i cannot have ANY of the music on my new laptop from the old account?????

Did I say anything close to that? I thought quite the opposite ("You can use items from other accounts on a computer").

As I said before, the occasion when people really run afoul of the authorization issue is when they get themselves in a position where they need to re-download (and I stress the "re"; yes, remember to see the "re" because we tell many people this and they never seem to get it) music from multiple accounts (say a drive failure) and they can't re-download from more than one account every 90 days.  This does not apply to new purchases.  If you always make sure you have a backup copy on another drive you never need re-download.

https://discussions.apple.com/message/24659889

Apple IDs and iCloud - http://support.apple.com/kb/ht4895 - including multiple AppleIDs, and backup

Can I Put Multiple iTunes Accounts on My iPhone? - http://techtips.salon.com/can-put-multiple-itunes-accounts-iphone-3518.html

https://discussions.apple.com/message/24882102 - I have purchases from my mothers Itunes account and fathers different Itunes account, so the music I would like to hear in my new itune library on a different MCBPro is split in two. So how can I authorise to [two] apple ids ?

Frequently asked questions about Apple ID - http://support.apple.com/kb/HE37

"I have multiple Apple IDs. Is there a way for me to merge them into a single Apple ID?

    Apple IDs cannot be merged. You should use your preferred Apple ID from now on, but you can still access your purchased items such as music, movies, or software using your other Apple IDs."