¿Cuáles son las tres notas que componen un acorde de Do mayor?

Understanding Major Chords

Major chords are built by stacking the 1st, 3rd, and 5th intervals from their parent major scale.

For example, in the C major scale, the notes are C, D, E, F, G, A, and B. Taking the 1st, 3rd, and 5th notes gives us C (1), E (3), and G (5), which forms the C major chord.