After updating to the new iTunes, my Play/Pause(f8), Forwad(f9) and Rewind(f7) buttons no longer work (Macbook Pro 13")

Hi,

I recently upgraded to OSX Yosmite and the new iTunes 12.

After upgrading, iTunes no longer responds to the Play/Pause, Forward & Rewind buttons on my keyboard.

I am using iTunes on a Macbook Pro 13" (non-retina version).

Any help to get these buttons to work again would be greatly appreciated!

Thanks,

Rawbex

Edit: I'm also currently re-installing iTunes on my Mac to see if that solves any of the problems I'm experiencing. This includes another issue that has appeared, where Google Play Music no longer recognizes iTunes. (Although, this separate issue will probably have to be solved by Google, not Apple).

Edit 2: Unfortunately, reinstalling iTunes did not solve or fix anything.