Pick Diatonic Triads & Tetrads
Major ModesSeven-note scales that contain all the triads and pentatonics
Hear any triad or tetrad from the major modes and identify its root and quality.
Why
Reproduce any chord in the key — triad or 7th — by ear.
Use your knowledge of the key to drastically reduce the number of options, or use your skills at finding the root and chord type