Free Tutorial on Chord Types
There must be thousands of chords, but all these chords are nothing more than a few chord types that have been transposed to several keys. If you learn to recognize the most important types, you will recognize the majority of the chords used in classical and in popular music.
Major is a chord type, so is minor. But do you recognize a major chord or a minor? A diminished or an augmented dominant 7th? Read the tutorial.
The level of this free tutorial is high, it is aimed at students of an Academy or Conservatory of Music. Download Chord Types (pdf).
This is Version 2, published in March 2016.
I advise you to install the free app Assistant Harmony Analysis. This app will help you understand the tutorial.