I'm confused about the C major scale and where the major chords are

[HutDave]

@stitch

The chords in a scale(key) come from stacked 3rds. Staying with the C major scale. C D E F G A B the 1st chord comes from the 1 3 5 intervals, the 2nd chord comes from the D F A the 2 4 6, the 3rd chord comes from the 3 5 7 E G B ect. If you look at the parent scale of the D chord the notes are D E F# G A B C# the 1 3 5 of the D major scale are D F# A but the notes in the 2nd chord are D F A the second note F(the 3rd of the scale) is flattened to a flat 3rd. This is why the second chord in the Key of C is Dm and not D. I’ll let you figure out the rest of the chords using the same formula

But shouldn’t the notes of the second chord of the D scale (therefore E) be: E G B?

[stitch]

Yes but that is Em(E G B) the second chord in the key of D.

E is E G# B coming from the 1 3 5 of the E major scale. E F# G# A B C# D#