I need to get my music from iPad to my Mac

Any Music/Media content, originally transferred from your PC/Mac using iTunes (or Finder on later Mac computers) - or “Paid” material downloaded from Apples iTunes Service - must again be synchronised to your iPad or iPhone. Your Music Library resides on your PC/Mac; iTunes does not support copying music back from an iPad or iPhone to a PC/Mac.

The reason for this intentional limitation, deliberately imposed by Apple, is to protect Copyright. In the case of iPadOS/iOS, Digital Rights Management (DRM) prevents direct copying of copyright material between devices is inhibited. This is intended to prevent the creation of illegal copies of potentially copyright material.

The iTunes Application on your PC/Mac maintains an authorised copy your media - whether this material is loaded from a CD, or downloaded from the Apple iTunes Service - and media derived from this library can be transferred to your iThings.

Are you trying to move music that has already been synchronised to your iPad from another computers installation of iTunes and your iTunes Music Library - or something else?