All I want to do is. . .
. . .record your screen on OS X.
How to record your Mac's desktop with minimal additional software
Contributors: anschwa Updated: 12/10/15
How to record your screen on OS X using QuickTime Player
Install Soundflower to enable system audio recording. Without
Soundflower, you will only be able to record audio from your microphone.
Audio Midi Setupand create a new multi-output device. Select Built-in Output, Built-in Line Output, and Soundflower (2ch)
Then rename the device.
To record system audio, open System Preferences Sound then under Outputs, choose your multi-output device (adjust your sound before hand)
Open QuickTime Player and start a new screencapture. Choose the audio to go through Soundflower (2ch)
Click on a screen to record there.
If you want to record on multiple monitors, then you have to duplicate QuickTime player in your Applications folder and start a new screencapture.
To remove the darkened screen affect, Hide QuickTime Player.