I haven't written in a while, but I've got a question for you. I decided I was going to expand my knowledge of the keyboard and learn some new cords. I decided to learn al the chords with 9, for example, C9, B9, D9, etc. So I found a web site that had all these chords for me and I stared to write down which notes and I noticed that C7 & C9 are the same, B7 & B9 are the same and on and on. Needless to say this has me a little puzzled. Can someone explain this to me? Thanks.