Why learn many many chords when you can learn the easy invariable concept called "intervals" and use them to construct chords ? My friend went to the "Berkley" of my place and really insisted that I should not learn chords from a poster or something. I mean, I've been playing for about 13 years, I know basic chords and wanted to move to some jazz chords and stuff. He said "construct them" and I was like "yeah wtf hey..." Then he said I only needed to know intervals, which I did. I learned intervals 10 years ago and only now do I know what to use them for. It's nice to know that the Third/minor Third decide if it's a major or minor chord. That type of thing. I'm a little curious to know how many of you already know this and if not who would be interested to.