How can I guarantee that audio only from my media player hits the speakers? I'm DJ-ing and I want to make sure that my music and nothing else is getting pumped out the speakers.

Undesirable things that may hit the speakers include:


Calendar.app reminders
Messages.app alerts
Calls (e.g. via FaceTime or Continuity)
Media playing in other applications, such as YouTube in my browser
System sounds (such as when you change the volume)


Of course, many of these things can be mitigated by turning WiFi off or fiddling with settings here and there. But it would be better if there was an explicit way to somehow specify that only audio from my media player gets to the speakers.

Is there a straightforward way to do this?
I don't know of an explicit way (I doubt there is one), but ClickToFlash and Do Not Disturb mode (Option click the notification center icon to toggle) will cover most of those things.

To disable the volume "popping" sound effect: open System Preferences > Sound > Sound Effects tab, and uncheck play feedback when sound is changed