11: Triadic Quality in Major

A chord is, very simply, what we call the simultaneous sounding of at least 2 different pitches. Chords have two key things that identify them—pun absolutely intended: first, the root of the chord which gives it its name; and second, the quality of the chord.

The most basic chords are what we call “triads”—they have three distinct notes. But, as I said just above, a chord is the simultaneous sounding of two or more pitches because there are situations in which you don’t need the third pitch to determine the quality.

The major scale is a good place to start looking for chords to build. A natural impulse, one which we will follow, is to simply start building chords on top of the notes of the scale. We will build bone fide triads for now, not omitting anything, even though we certainly could—we’ll start omitting soon. We’ll do this by imagining a C major scale that goes on as far as we need it to: C D E F G A B C D E F G A B C D E F G A B C …. And so on.

The scale itself starts on C, so let’s start there. C is the most important note of the C scale, so naturally, the C chord is going to be the most important chord built from this same scale.

To build the chord on C we’ll get from C major (spoiler alert, the chord itself will be C major), simply start from the note we intend to be the root, and stack two consecutive thirds.

C, then C plus a third is E, then E plus a third is G.  

For the next several chords, just do likewise:
D, D plus a third is F, F plus a third is A.
E, E plus a third is G, G plus a third is B.
F, F plus a third is A, A plus a third is C.
G, B, D.
A, C, E.
B, D, F.

Here, there are exactly three different qualities of triads, and whatever major scale you chose (try G quadruple flat for all I care [please don’t, that’s a terrible mess]—it’ll work exactly the same, I promise!).

Here are the possible qualities and how to find them:

a. If the bottom third is major, so is the triad
b. If the bottom third is minor and the top third is major, the triad is minor
c. If both triads are minor, the triad is diminished

With that in mind, the qualities will be the following:
The triad built on the first degree of a major scale will be major.
The triad built on the second degree of a major scale will be minor.
The triad built on the third degree of a major scale will be minor.
The triad built on the fourth degree of a major scale will be major.
The triad built on the fifth degree of a major scale will be major.
The triad built on the sixth degree of a major scale will be minor.
The triad built on the seventh degree of a major scale will be diminished.

We write this with Roman numerals—uppercase for major, lowercase for minor, and lowercase followed by what looks like a “degree” symbol for diminished: I, ii, iii, IV, V, vi, vii°. Again, this pattern of Roman numerals (and the qualities that they refer to) will be the same for any major scale you choose.



 

Comments

Post a Comment

Popular posts from this blog

35: Figured Bass

Image
  There’s a system of notating harmonies that’s rather unique to the Baroque era, but which is so frequently used there, and so important to it, that no discussion of theory would ever be complete if we did not cover it. This is the notation of figured bass: “figured,” in the sense of using figures (numbers) to notate the bass. Figured bass was, in a sense, its own notation completely separate from the five lines and four spaces of the staff, which was nearly exclusively the purview of cellists, bassists, harpsichords, and organists.  Figured bass, fair warning, can be intimidating at first. But, just as with anything else we’ve covered so far, the more you practice reading it, the better you’ll get.  In this system, we use numbers to indicate intervals above the bass. We stack them, and this is how we build chords. If you can’t stack them, nowadays, it’s perfectly fine to use slashes and write the numbers horizontally.  Let’s start with the easiest figured bass nota...
Read more

58: Swell pedals and swell shades

There’s one pedal that we haven’t discussed on the organ because it isn’t one of the “note” pedals—in fact, it’s the only one that doesn’t have a pitch. Instead, the missing pedal is the swell pedal. Look at the body of the organ (the assembly of where all the pipes are, as opposed to the “console”, where the organist sits and plays the instrument—these may or may not be physically close to each other), and you’ll probably see what kind of look like plantation shutters. (If you know where my parish is, then this feature of the organ is very clearly visible on ours. Your local organ might not be so obvious.) These shutters, called “swell shutters/shades,” show or hide the pipes of the organ. Organs have instantaneous dynamic control—the amount of pressure you put on a key dictates how much air flows through the pipes, just like a piano allows you to adjust dynamics on the fly by changing the amount of pressure with which the hammer hits the string(s) given the pressure on the key. Thes...
Read more

54: Trills in the Baroque vs. Classical Periods

Image
Baroque music is known for its incredibly technical and ornamented style. The most common and fundamental of those ornaments is our focus today: the trill. Most simply, a trill is a very fast, repeated alternation of two notes. In the vast majority of cases, those notes are adjacent, but that is not a requirement. Given how fast and common they are, regardless of what you play—whether it’s a string, wind, or keyboard instrument, or your voice—they have a reputation for being quite tiring to play. The period matters when considering a trill. Classical and later composers treat trills, in a sense, in the opposite manner than Baroque composers do. Let me show you two examples: First, the Baroque way of thinking. This is a PAC:   and especially in the Baroque era, when the plucked harpsichord dominated over the hammered piano, it was hard to sustain sounds for long since the sound of the plucking decays quickly. The trill was developed in response, out of a need both to ornam...
Read more