| It basically comes down to limiting yourself when improvising. In this case, to four notes, and the particular four notes I have used in the video are the most basic ones to start with and sound most in unity wwith the chord you are playing over them.
If you have a library I recommend Jerry Bergonzi's Vol1 Melodic Structures Book, to be honest you don't need to buy it as it is about 100 pages, but if you get the idea of the concept down, you can work the rest out yourself.
The way I look it is there are three basic cells you can play over a chord using the following notes (the numbers are the degree of the scale) with each one using more upper extensions. Of course there are other cells, but limiting yourself at first will help you get a greater understanding of this technique. Here are the three cells you should start with:
Major or Dominant (1 2 3 5) (5 6 7 9) (9 10 #11 13) If you notice each of these are exactly the same 'shape' on the bass, just starting on the root, 5th or 9th. Be careful with the 5 6 7 9 shape on the dominant though as it will create a major 7 instead of dominant 7. You can either alter it, miss it out, or just play it and see if you like the sound.
Minor7 (1 b3 4 5) (5 b7 8 9) (9 11 12 13) If you notice each of these are exactly the same 'shape' on the bass, just starting on the root, 5th or 9th.
So as I said in the other post each cell has 24 permutations, and including inversions, 96! permutations. So, now you know 3 shapes for each of the basic chord types, thats 288(!!) different things you can already play on a particular chord, just buy starting of with this one shape. I personally find it really interesting.
So to be honest, even if you only learn the minor shape and major shape, you can plag your play through a set of changes quite easily without even thinking what notes you are playing, but ideally you want to understand every note you play and why it is being played. | 
