|I play 5-string banjo, mandolin and guitar. Back in 1988, I had reached a point in my musical development when I needed to understand chords:|
|1) I wanted to dig deeper into jazz music.
2) In order to reduce hand movements, I wanted to be able to place the next chord close to the chord I was already playing. Playing would be easier and I would get a smoother sound.
3) Being able to build a chord around a certain melody note, I could play both melody and harmony together.
There were chordbooks with millions of little black dots. They showed very few chords, and the dots were impossible to memorize because there was no system. I had to buy a new book for each instrument. That was not what I wanted.
Then there were musical theory books, filled with strange words and written music. That's how I learned. I really had to work hard to learn what I wanted. When I finally got the grasp of it, I realized: It is very easy to build chords! It can be explained without a lot of fancy words, and you don't have to read sheet music. For my own benefit, I developed the Chordkey-method.
Nowadays there is chord finder software you can download from the web. Most of them are pretty much like the chordbooks. Still, it is much more convenient to know how to build a chord when you need one - you can't bring the computer everywhere.