# What is the logic behind a chord consisting of the 3rd, 5th, and 7th of a chord with the root of the chord in the bass? [closed]

What is the logic behind a chord consisting of the 3rd, 5th, and 7th of a chord with the root of the chord in the bass?

• What kind of "logic" are you after? Can you provide an example of the sort of logic you mean? I'm sorry but I don't understand what you're asking. – piiperi Reinstate Monica Dec 7 '19 at 10:13
• One of the 'logics' is that it happens to sound good (to Western ears at least), so gets used. Are you asking for scientific/physics reasons? – Tim Dec 7 '19 at 10:20
• @piiperi Seems that OP is asking what's the logic behind building chords using stacked thirds, as opposed to any other way. – Von Huffman Dec 7 '19 at 20:14
• @Lyd like, why not build a chord by stacking seconds or fourths or fifths, instead of thirds? Uh... try it and see how good it sounds. – piiperi Reinstate Monica Dec 7 '19 at 20:23
• @piiperi So there's a reason behind it! That's what OP is looking after. And there's quartal and quintal harmony, so plenty of people have tried to use alternative frameworks. There's a question right now at Meta that ask why our engagement is so low, and one of the most obvious reasons is that a lot of us are more worried about ranting about every single thing in the comments, than helping the question being useful to many, or more focused, etc. The question is pretty straight forward to me, yet it has 3 close votes because it "needs clarity". – Von Huffman Dec 7 '19 at 20:44

With my answer I’ll try to make understandable your question for other users. It is a translation of an abstract/thesis:

Opening lecture: The logic of chords Prof. Dr. Ingolf Max (Leipzig)

A logic can be understood as the specification of a set of constitutive rules for a formal game. That these rules set the internal meaning of all involved in this game.

Harmony can be understood as the internal relationship between chords and thus as the internal meaning of music.

The constitutive rules include the specification of the logical space. This is the room of the whole game. This also means that anything that can not be related to this space can not be grasped with this logic / game.

The logical space of the representation of chords and the harmonic relations between them is the chromatic scale (the logical tone space).

Constituent determinations include the indication of the smallest units to which all further operations should refer. In the logic of chords, I assume that not the sound, but the chord is the smallest unit. Chords are considered as two or more directly related intervals. That is, the smallest units of our logic are, so to speak, specific molecules.

A consequence of this representation is that more complex chords (e.g., "consisting" of 5 or more tones) may contain multiple subpatterns which are identical in their interval structure to certain chords.

The chord c'-e’-g'-b 'contains the contiguous subpatterns C-major c'-e’-g', E-minor e’-g'-b 'and the non-contiguous subpatterns c'-g'-b 'and c'-e’-b' (both certain "incomplete" seventh chords).

Another consequence of this representation is that even between two chords there are always harmonic relationships due to their internal structures. Harmonic relationships are not created in addition, but are always present with the sound of several chords.

Source:

https://logmusicblog.files.wordpress.com/2014/04/zur-logik-der-akkorde.pdf

That's a major 7th chord in its first inversion. According Jimmy Bruno's approach to studying "jazz" or extended chords on the guitar, if a chord has 4 notes, know that it has 4 inversions, all being;

1-3-5-7

3-5-7-1

5-7-1-3

7-1-3-5

That's it. Unless if you are looking for a different "logic behind".

• 1-3-5-7 is root position - the others are inversions, thus the 1st inversion is actually 3-5-7-1' With a 3 note chord, there's root, 1st and 2nd inversion. So with a 4 note... – Tim Dec 7 '19 at 10:22
• In short; a 4 note chord has 4 different ways of voicing it. – Phemelo Khetho Dec 7 '19 at 10:33
• With closed voicings, yes. With open, there are several more voicings available. – Tim Dec 7 '19 at 10:56

Overall, it's a root position 7th chord. Taken alone, the upper part is a simple triad, or possibly a 7th chord with the root missing. But it ISN'T alone! The root's in the bass, and is part of the harmony.