Play button (media buttons) behavior has changed for the worse.

Yep you should logout, user preferences are loaded during logon.

again... contact apple on Twitter Apple Support (@AppleSupport) | Twitter and tell them you are ****** with this behavior. Link to this thread too, so they can see that you aren't alone.

Here, download this app and it will bind your media keys to iTunes or Spotify: http://milgra.com/high-sierra-media-key-enabler.html

(only works for physical keys not the touch bar yet)

Also be sure this checkbox is NOT checked:

If it is checked you need to hold down the fn key to get the normal response from those keys.

I disagree. It is USELESS for YouTube. If you are watching a YouTube video you can press space bar on your keyboard to play/pause it. So now, if I am on a page with a YouTube video I have two buttons to play/pause the YouTube video, and zero buttons to play/pause my iTunes music.

I figure if you are a super-newbie with computers, the kind that can't deal with doing two things at once, then you might be listening to music. You might decide to stop that music, so you could open your web browser and watch a video, then close that when you're done, go back to your music and play it again. The current button behavior would work great for that scenario, people who are just learning how to use a computer. Of course, in that scenario, who even needs shortcut buttons if you're only doing one thing at a time. Other than that, yeah the current button behavior is completely useless, defeats the whole purpose of having shortcuts.

Also remember that iPhoto/Photos used to steal the iTunes keyboard shortcut buttons in the same way, for years. But now that Safari is doing it too, and doing it in a really poor way (sometimes play makes random html5 sound effects on a web page play), it's extra annoying because people tend to ALWAYS have safari open. Not so much with their photos.

I am too struggling with this new "feature" and would prefer the old behaviour, here is the feedback I just submitted:

Hi in High Sierra the media key behaviour has changed. My usual flow is while listening to music in iTunes and browsing the web and begin to view a video I usually press the pause key to pause the music. Instead it pauses the video! There are a few other issues with this behaviour like after the video ends the media keys still don't return to iTunes and the tab has to be closed. Also sometimes it's hard to understand which application has captured the media keys, e.g. sometimes I press play and something is playing and after I've quit Safari, and iTunes I then find that Reeder is playing a video even though one isn't even displayed. I'd like to request that an option is added to the keyboard settings to return to the original behaviour of the media keys only controlling iTunes thanks.

Visit a YouTube page but don’t play yet.

Command+tab to switch to iTunes.

Press space to pause.

Command+tab to switch back to safari.

Press media play key and hopefully the video plays.

Otherwise quit every app until the media keys work in Safari. In my case usually Reeder has captured the keys.

Wondering what do touch bar Mac users do

raheel.sadiq'ssolution in this link helped solve the problem for me.

media keys not working in MacOS High Sierra | Apple Developer Forums

Just a reminder everyone, go here and complain about this:

Feedback - macOS - Apple

Whoa, that's crazy, I was just about to post a link to a similar app that I wrote! Free for anyone who might find it useful: http://stuntsoftware.com/reflex/

I haven't really announced it publicly anywhere else yet - feel free to write dan@stuntsoftware.com with any feedback!

Thanks,
Dan

We aren’t saying the media keys don’t work. We are saying high Sierra has changed the way they work. If you just open up iTunes and use them it will work fine, but then if you navigate to a web page with some sort of media (video/music player) and you push the pause button to stop your iTunes music, it will instead play/pause the media on the web browser. You then have to manually bring iTunes back up and click play/pause.

To me this totally defeats the purpose of shortcut media keys. If I can’t use it to control a background app it’s useless.

I'm typing this in Safari. And I'm using the media keys to open, start, stop, go forward and backward, any track in iTunes - from Safari, from Mail, from Calendar and from any other open app I'm using. But before I emptied the caches, the media keys didn't work in iTunes at all.

Of course, if you open Youtube or any other Media app and keep that in the foreground, the media keys will act on that app or window, as they should. In that case, but only in that case, the media keys control the media in the active window. Which is totally logical in my view - the OS correctly assumes that you want to control the active window when that active window has media in it.

Try this once and let me know.

Play music on iTunes. In safari go to YouTube and pull up any video. Once the video starts playing push the pause button on your keyboard.

In my case, it pauses the video and NOT iTunes. This is not how I want it to work. I don’t want shortcut keys for YouTube.

This is a good attempt but a moot point. The media keys work, but they only work on iTunes until you open something else up such as youtube or a facebook video. Once you do that the active thing takes over and won't go back to controlling iTunes until you close the tab with the media. This is such a stupid move from Apple and I'm quite tempted to revert my iMac to Sierra because of this idiotic change. Half of the videos on Facebook are nothing I would want to watch, and if I want to watch a youtube video I pause iTunes and then control youtube with a click. I really hope they fix this or at least give their users an option because this is the dumbest thing I've ever seen and a major setback. 😠