Answer:
three tones
Triad, in music, a chord made up of three tones, called chord factors, of the diatonic scale: root, third, and fifth. The system of diatonic triads is the basis of tonal harmony in music. Triads built on the notes of the C major (and natural A minor) scale.
Leonardo da Vinci was the only artist not involved in the creation of Saint Peter's Basilica and the Vatican out of those four.
None. I need the points, sorry!