Major Triad
Root, major 3rd, perfect 5th — the most consonant chord
Symbols: C · Cmaj · CM
The major triad is the root, major 3rd, and perfect 5th — built from the first five harmonics of the harmonic series, which makes it the most consonant three-note chord.
Each major mode generates three major triads, and roughly 80% of all chords in popular music are major or minor. It contains the root & 5th and is contained by the major pentatonic and the major 7th and dominant 7th tetrads.