Prevent Music.app opening when connecting Bluetooth device

I haven't tried disabling RCD in Catalina. The commands I used for Mavericks are

launchctl stop com.apple.rcd

launchctl unload -w /System/Library/LaunchAgents/com.apple.rcd.plist

I don't see a "com.apple.rcd" file on the Catalina System volume, although there is a plist version. Instead, there are two other files, com.apple.rcdevent.matching and com.apple.rcdevent.matching.plugin. Also, I'm a bit out of my depth here. I assumed that I couldn't alter System files on the Read-only volume. Perhaps those commands merely stop and prevent loading of RCD but don't change the files?

There is another (nuclear) option at StackExchange:

sudo chmod 000 /System/Library/CoreServices/rcd.app/Contents/MacOS/rcd

sudo pkill -9 rcd

There is an rcd.app in Catalina with the same path as shown above.

But, again, my comfort zone with Catalina is far narrower than it is with Mavericks. I'll have a look at the man page. I'm waiting to hear from Yamaha.

Thank you.

Thank you for your reply. The receiver is just like any old school stereo receiver-amplifier, except that it is also designed to accept audio input from Bluetooth devices. That function is selected from the receiver control panel. I purchased the receiver because I wanted to stream audio from my two Macs to the receiver (via Bluetooth) so that the receiver would then output the audio to my old school speakers.

The whole thing works perfectly (no software came with the receiver; one pairs it just like any Bluetooth device). It's just that I don't (necessarily) want to use the Music.app, which, as I said, launches on its own, and, worse, immediately starts playing. I'm a writer/editor; consequently, I spend large amounts of time in front of the computer. I listen to Internet streams, lots of them. I use a nice, simple application, SonicWeb (it's in the App Store) dedicated to finding, storing, and recording streams. It's much handier than Apple Music.

I understand Apple's motive, but Music.app doesn't suit all my desires; thus, it is annoying to have it shoved in front of me every time I activate the receiver, and even after I quit the application. Can that behavior be made optional (I promise to keep it a secret)? Perhaps someone at Apple will see my plea.

Thanks for reading my posts.

Thanks for your thoughtful reply. I too have not found settings in either Music or Bluetooth to account for what happens, which is why I ended up here. I can't say whether my receiver has a "resume play" command (I've scoured the manual), but I don't think so for the following reason. Situation: Music is not open. SonicWeb is not open. Turn on receiver and select Bluetooth from the receiver control panel. Music (only) launches; SonicWeb does not open. Quit Music quickly and open SonicWeb; play streams (Music does not re-open, all is well). Quit SonicWeb. Turn off receiver. Later, repeat the same process. Music again launches, etc.

If the receiver was sending a resume play command, why doesn't SonicWeb open? It was the last application to be playing. Or is only Music able to receive a resume play command via Bluetooth.

Also, SonicWeb doesn't use a separate set of media buttons. It has its own Play/Pause/Stop/Record buttons (no Next or Previous) within its GUI. SonicWeb doesn't use a web browser interface, despite the name of the application. It's free-standing.

I suppose my best option at the moment is to contact the receiver manufacturer (Yamaha) and inquire about an undocumented "resume play" action.

Parenthetically, I had the same issue with iTunes on an older Mac. But, as I mentioned, I found some Terminal commands (at StackExchange, I think) to prevent activation of the RCD (remote control daemon). Does the same autoplay behavior with iTunes and Music imply that my receiver is at fault?

Many thanks.

No Joy. I issued the two launchctl commands, and Music.app still launches and plays. I rebooted, to no avail. Do I need "sudo" in front of those commands? Terminal did not return any errors without it. Otherwise, I give up.

Thanks for all your input.

Thank you for the “sudo” heads-up.  Unfortunately, there is a new barrier.  Both of the following commands return “Could not find specified service”

sudo launchctl unload -w /System/Library/LaunchAgents/com.apple.rcd.plist

sudo launchctl unload -w /Volumes/New\ Mini/System/Library/LaunchAgents/com.apple.rcd.plist

I noticed in the launchctl man page that “load/unload” are legacy commands and the -F flag may be necessary.  Does that account for the failure to find the service?

I also noticed “… allowing non-root write access to the /System/Library/LaunchDaemons directory WILL render your system unbootable.”

I’m not 100% sure what “allowing non-root write access” means, but I think it’s time for me to forget about messing with rcd. I'm probably one of maybe five people in the world who cares, and you, and I, have spent a grossly disproportionate amount of time on this trivial issue.

Thanks for all your feedback. I've learned some things, which is a plus.

Got it. Thanks for the explanation. I'm still curious to hear from Yamaha (I can't understand why I am apparently the only one with the issue). Then I'll issue the launchctl commands.