First attempt at merging video and audio. Pretty easy with ffmpeg on Linux. The chess video is no longer a silent film. Microsoft allegedly has an equivalent ffmpeg. ffmpeg may also be known as libav or avconv.
$ ffmpeg -i git.mp3 -i chess.flv chess.mp4
Pretty lucky here as the video and the movie were about the same length. Being a film editor must be fun, We will do more complicated stuff later. Makes for much respect for noted film maker Ken Burns and all his crew.
Do not have a guitar anymore, but again that was me playing the guitar.