I have a new apple ID account. My Ipod has music from an old forgotten account ID. How can I get my Ipod music downloaded to my computer?

Not normally. See if you can recover the ID/password. An iCloud e-mail address is an Apple ID. Use every email address you can think of.

Apple ID - How to find your Apple  -  

Apple ID - Find  -     

Other ways to find your Apple ID

You can check if you're signed in to the App Store, FaceTime, or Messages on your iPhone, iPad, iPod touch, or Mac, or check if you're signed in to iTunes for Windows on a PC. You can also go to iCloud.com or appleid.apple.com and see if your Apple ID prefills on the sign-in screen.   

If you forgot the Apple ID (iCloud) password, enter the Apple (iCloud) ID, and click Forgot Password. See if you can get a Rescue or Notification email option if necessary. Link to contact Apple Support at the end of the 2nd article.

Apple ID - Manage  -     

Apple ID – Forgot Password  *      

If you can recover the ID, you can try setting up Family Sharing between the IDs if you want to be able to share purchases made with the IDs.

Family Sharing.   *

ASC YouTube for Family Sharing

Family Sharing - Set up.  *

Family Sharing - Set up on iPhone.  -

have a Mac purchased New May 2020. Set up the new Music App and now I would like to download my iPod music to my Mac

You can't get the music without the old ID. The purchases are tied to that ID. Unless you can recover the old ID, you will need to purchase the music with your new Apple ID.