The first note of the scale is called the tonic.
So the tonic triad of C major begins on C.
1
3
5
tonic 3rd
5th.
E is the 3rd of the chord. G is the 5th of the chord.
Click twice to hear it.
The tonic can also be called the root of the chord.
The key signature
has no sharps or flats.
The relative minor of C major is A minor. This also has no
sharps or flats in the key signature.
The tonic triad of A minor begins on A.
The 3rd is C and the 5th. is E