What stage is the D7, or the music catechism built on?

Can you tell me on which level the dominant seventh chord is built? With such a question to me sometimes beginners solfezhisty. How not to tell? Indeed, for a musician, this question is from the catechism.

By the way, do you know the word catechism? Catechism is an ancient Greek word, which in the modern sense means a summary of any teaching (for example, religious) in the form of questions and answers. This article also represents a circle of questions and answers to them. We will understand at what stage D2 is built, and at what D65.

Question: At what stage is the D7 built?

Answer: D7 - this is the dominant seventh chord, it is built on the fifth step, consists of four sounds, located on the third. For example, in C major, these will be sounds: salt-si-re-fa.

Question: At what stage is built D65?

Answer:D65 is the dominant sexthkord, the first appeal of the D7 chord. It is built from the seventh stage. For example, in C major, these will be sounds: sire-fa-sol.

Question:What stage is the D43 built on?

Answer:D43 is the dominant tertz-quartakcord, the second appeal is D7. This chord is built on the second stage. For example, in the key in C major it is: re-fa-sol-si.

Question:At what level is the D2 built?

Answer:D2 is the dominant second chord, the third appeal is D7. This chord is built from the fourth stage. In the key in C major, for example, D2 is located by the sounds: fa-sol-si-re.

In general, it would be nice to have a cheat sheet, looking at which you could immediately see where a chord is being built. Here you have such a sign, write yourself in a notebook and then, you will always have it at hand.