Hello darrenohagan,
Welcome to Apple Support Communities.
We understand that you’re not able to control music ion the Music app with the control buttons. We are happy to help.
We’d like to have you do some isolating troubleshooting steps. Let’s start with testing in safe mode using the steps here: How to use safe mode on your Mac - Apple Support
"Intel processor
- Turn on or restart your Mac, then immediately press and hold the Shift key as your Mac starts up.
- Release the key when you see the login window, then log in to your Mac.
- You might be asked to log in again. On either the first or second login window, you should see ”Safe Boot” in the upper-right corner of the window."
We’d also like to have you set up a new user account to test using the steps here: Set up users, guests, and groups on Mac - Apple Support
"Add a user
- On your Mac, choose Apple menu > System Preferences, then click Users & Groups.
- Click the lock icon to unlock it.
- Enter an administrator name and password.
- Click the Add button below the list of users.
- Click the New Account pop-up menu, then choose a type of user.
- Administrator: An administrator can add and manage other users, install apps, and change settings. The new user you create when you first set up your Mac is an administrator. Your Mac can have multiple administrators. You can create new ones, and convert standard users to administrators. Don’t set up automatic login for an administrator. If you do, someone could simply restart your Mac and gain access with administrator privileges. To keep your Mac secure, don’t share administrator names and passwords.
- Standard: Standard users are set up by an administrator. Standard users can install apps and change their own settings, but can’t add other users or change other users’ settings.
- Sharing Only: Sharing-only users can access shared files remotely, but can’t log in to or change settings on the computer. To give the user permission to access your shared files or screen, you may need to change settings in the File Sharing, Screen Sharing, or Remote Management pane of Sharing preferences. See Set up file sharing and Share the screen of another Mac.
- For more information about the options for each type of user, click the Help button in the lower-left corner of the dialog.
- Enter a full name for the new user. An account name is generated automatically. To use a different account name, enter it now—you can’t change it later.
- Enter a password for the user, then enter it again to verify. Enter a password hint to help the user remember their password.
- Click Create User.
- Depending on the type of user you create, you can also do any of the following:
- For an administrator, select “Allow user to administer this computer.”
- Use Sharing preferences to specify whether the user can share your files and share your screen.
For information about Apple’s privacy policy, see the Apple Privacy Policy website.
If your Mac has Touch ID, a new user can add a fingerprint after logging in to the Mac. The user can then use Touch ID to unlock the Mac and password-protected items, and purchase items from the iTunes Store, App Store, and Apple Books using their Apple ID. See Use Touch ID."
Let us know if you have further questions.
Take care.