Use only audio when mixing compositing and sequencer in post processing I created a nice movie layout using only the Node editor. I added an mp3 audio file via the video sequence editor. Selected Both compositing and sequence in post processing under render properties and clicked the animation button and got a nice mp4 movie. 

When I replace my mp3 file with a movie clip (containing both audio and video) in the video sequence editor and hide the movie by clicking the eye and set opacity to zero + moving the clip outside the start and end frame interval, I get an undesired result. The generated output movie does not contain any video, only audio.
Instead of hiding the movie clip in such an laborious way, just select it and delete it. Make sure you have only the movie clip selected, and nothing else.