Hi adamsurryhills,
It’s never fun when you hear static noise when playing music via iTunes on your MacPro, and we can help you figure out why that’s happening. Before we jump in and start, can you please provide more information? For example, have you made any recent changes to your Mac that might have caused the audio distortion you’re hearing? Also, have you checked to ensure that your internal speakers are working correctly? If you haven’t, please try the steps in the link below.
If the internal speakers on your Mac aren't working
Please remember that if you hear distorted sound from the built-in internal speakers on your Mac, we suggest you make sure macOS is up to date and check your settings.
With that being said, to perform the troubleshooting actions that we recommended via the article above, please read through and complete the steps in the section titled “Check your sound settings.”
We recommend the steps above because they move our troubleshooting efforts towards a resolution by helping resolve the issue you initially reached out to the community about, which is you hearing distorted sound when playing music on your MacPro.
If the original problem persists after trying the previous steps, please provide us with specifics on what you see for more help, and we will continue from there.
Thanks for using the Apple Support Communities.
Cheers!