Why is there no full triad as the last chord in 4 part counterpoint?

1. What is an incomplete triad?
2. What is a four part chord?
3. Can you double the third in part-writing?

What is an incomplete triad?

Incomplete Triads

It's the least active of the notes and its absence is barely noticed. It's the 3rd of the chord that gives it its distinctive major or minor character.

What is a four part chord?

Four-part harmony is a traditional system of organising chords for 4 voices: soprano, alto, tenor and bass (known together as SATB). ... Secondly, the four voices are singing at the same time so their notes are combined into one sound. At any one moment, the music consists of 4 voices each singing one note.

Can you double the third in part-writing?

In diminished triads, double the 3rd (not a note of the tritone). ... In Incomplete triads, triple the root, include the third, and omit the fifth. In Incomplete seventh chords, double the root, include the third and the seventh.