Well, at least it's short!

I've posted a few hubs where all the material is in the same key - if you check them out it might help you in understanding this post. In my opinion music theory as taught is always too complex. If you learn one key really well, all the relationships (chords, intervals, scales, inversions) can be transferred to all the other keys.

The numbers especially turn people off, but they are crucial - a number just tells you the distance from the starting note, so C6 just means a C chord with an A added-

C D E F G A

The last couple of bullet points are guitar-centric, but the note sequence is the same for piano or keyboard, and also bagpipes!

Note names - there are no flats or sharps between B and C , E and F - all the other notes have them.

The material shown here is all you need to start songwriting - and using Garageband for instance, you could be creating your own tunes in a very short time. If you take other songs apart and reassemble them it's a great way to learn fast - just as taking cars to bits will give you some insight into how they work.

Also look at my other hub Music theory - cycle of fifths, it might help.