Triads are built with roots, thirds and fifths, and they form the basic harmonic building blocks of most pop songs. Songs in major keys are often built around the chords I, IV, V and vi. ii and iii are also possibilities, but are used less frequently.
Now that we have some understanding of how scales and keys work, we can begin to think about chords, and how they fit within keys. If you’re interested in writing songs, you’re probably already somewhat familiar with chords, which often are the first musical materials a guitarist learns to play.
The most basic chords in Western music are called triads, in which we have a root (the main note of a chord) along with a third (a note a third above the root) and fifth (a fifth above the root). We can then take these triads and add the same notes in various octaves without changing their character much.
The most common types of triads in Western music are major chords and minor chords. You’ve surely encountered these if you play a chordal instrument. To construct a major chord, pick a root, then add a major third and perfect fifth above it.
Major triad = root + major third + perfect fifth
The example below is an F major chord. F is the root, A is a major third above F, and C is a perfect fifth above F. Notice that the triad below is written as three consecutive spaces on the staff. A hallmark of all triads is that, once you reduce them to their three basic note names, they can be written on either three consecutive spaces or three consecutive lines.
Each minor chord consists of a root, a minor third above that root, and a perfect fifth above the root.
Minor triad = root + minor third + perfect fifth
The only difference between a minor chord and the major chord with the same root, then, is that the third (which is, somewhat confusingly, actually usually named as the second note of the chord) is a half step lower. Here, for example, is an F minor chord – it’s the same as the F major chord, but with an Ab in place of the A.
If you already play a chordal instrument, you’re likely already able to play the major and minor chords. Heck, if you play the guitar, it’s as easy as just making a barre chord shape and moving your left hand around the fretboard. Here are our basic major chords (keeping in mind that sharps and flats reset after each bar line).
Here are our basic minor chords. (I’ve changed a few of the roots to their enharmonic equivalents to simplify some of the chord spellings.)
We can approximate the chord progressions of many pop songs with just those 24 chords. And if we’re writing our own songs, we can further limit our choices, at least to start, by writing only using chords that fit into the key in which we’re writing.
How Chords Work Within Major Keys
Let’s assume that we’re in the key of G major. You may have noticed that if you’re playing a song in the key of G, you will frequently see the following chords:
G major (or just “G”): G B D
C major (or just “C”): C E G
D major (or just “D”): D F# A
The notes of these chords are all part of the G major scale.
G A B C D E F# G
Those three chords contain all the notes of the G scale, and no others, so we can deploy them in many situations in which we’re writing in G. But there are other chords we can use as well. To see them all, let’s make a G major scale.
The numbers below the notes are scale degrees, which refer to which note they are in the scale. I use “1” for the last G to match the “1” for the first G, and to show that the scale resets when it spans an octave.
Now let’s create a triad (which we’ll spell for each note with three consecutive lines or three consecutive spaces) with each note of the scale as the root.
We’ve replaced the scale degrees on the bottom with Roman numerals (I, ii, iii and so on), which we use to indicate the roles of chords within keys. No matter what major key we’re in, the I, IV and V chords will be major, and we indicate that in Roman numerals by using capital letters. The ii, iii and vi chords will be minor, which we indicate using small letters. The viio chord is diminished. We won’t use viio very often, so don’t worry about that too much just yet.
It’s helpful to think about chords as Roman numerals because doing so makes it easier to appreciate the relationships between chords no matter what key we’re in. Roman numerals also help us make easier mental transitions between keys. If you play guitar, think of the Roman numeral system as the mental equivalent of a capo. (Play a song in the key of G, then move the capo to the second fret. Now we’re in A, but the relationships are exactly the same.)
These chords – with one key addition that we’ll discuss later – will form a basic palette that we can use whenever we’re writing a song in major.
Note, again, that we can use this same pattern (I, ii, iii, IV, V, vi, viio) for any major key. For example, here is our basic chord palette in F major:
F Gm Am Bb C Dm Eo
I ii iii IV V vi viio
And here it is in B major:
B C#m D#m E F# G#m A#o
I ii iii IV V vi viio
Already, this set of chords provides us with a large array of colors. Well, maybe not a large array of colors, but one that’s big enough for much of what we want to do.
The Basic Chords: I, IV, V and vi
Many pop chord progressions are very simple, and we can replicate a large percentage of the pop and rock libraries from the last few decades with just a few basic chords: I, IV, V and vi. In fact, we can just take those four chords, put them in any order, and build a pretty good pop song on top, as long as we do a nice job with the other elements. (Of course, “doing a nice job with the other elements” can be incredibly tricky, but at least our basic chord progressions are pretty easy.) The Australian comedy band Axis of Awesome prove that point with “4 Chords,” a six-minute song that features bits of dozens of popular songs that use exactly the same I-V-vi-IV progression.
We can also easily come up with examples of different progressions using the same four chords, particularly progressions that begin with I. (An entire website, http://clicheprogressions.com, exists to document which songs contain these progressions.)
I-vi-IV-V (also known as the “50s progression”): “Baby” (Justin Bieber), “Happiness is a
Warm Gun” (The Beatles), “Unchained Melody” (Righteous Brothers)
Incidentally, some of the songs above are terrific, but some aren’t. This shouldn’t trouble us. The fact that the spectacular “Unchained Melody” and the somewhat less spectacular “Baby” have the same chord progression suggests that chord progression isn’t the biggest factor in a song’s quality. In fact, in some cases, we might shoot ourselves in the feet by worrying too much about writing chord progressions that are unique.
In addition to the progressions listed above, some progressions beginning with IV (such as IV-I-V-vi) are also common, and many three-chord progressions featuring these same four chords are commonplace as well.
Throughout this site, we will learn about ways of incorporating distinctive elements into our chord progressions, but probably the best way to proceed, at least if we’re interested in writing pop songs, is to stipulate that these so-called “cliché progressions” are clichés for a reason. Pop songs are catchy, at least in part, because they feel familiar, and the best pop songs often feel like something you could swear you’ve heard before. Even if our eventual goal is to stretch the boundaries of pop music, perhaps the best approach is to learn from these progressions, embrace them, and build from them, and not to ignore them completely. The I-V-vi-IV progression is a cliché, but it can also be our friend.
It’s especially important that you become fluent in naming the I, IV, V and vi chords in various keys. These chords are very likely to arise again and again in your writing and in your performing. So if you don’t yet feel totally confident in your knowledge of these chords, this might be a good time to pause and think through what those chords would be in a number of major keys.
|Quick Quiz 3.1
Name the I, IV, V and vi chords in each of the following keys.
|Quick Quiz 3.2
Listen to the prechorus of Imagine Dragons’ “Thunder.”
The song is in the key of C major. What are the Roman numerals for the progression of C-Am-F?
The Other Chords: ii, iii and viio
Now let’s return to the palette above. Here it is again.
Let’s turn our attention to the ii, iii and viio chords. These chords appear less often than I, IV, V or vi, but they’re still important. The ii chord, in particular, is fairly common. It frequently occurs immediately before V or IV, and rarely goes straight to I. The ii chord also shares two notes in with IV and can be substituted in most situations where we might use IV – try, for example, changing the I-vi-IV-V “50s” progression to I-vi-ii-V. Aretha Franklin’s “Baby Baby Baby” uses this progression in the key of G, for example (G-Em-Am-D).
Similar progressions involving ii also work. Both the verse and the chorus of Semisonic’s “Closing Time” use a I-V-ii-IV progression (G-D-Am-C). The choruses of the Temptations’ “My Girl” and the Dixie Chicks’ “Wide Open Spaces” use a common and very effective progression of I-ii-IV-V. The chorus of R.E.M.’s “Fall on Me” uses that same progression, I-ii-IV-V, in the key of C (C-Dm-F-G). The verse of the song also begins on ii and alternates between the ii and vi chords, establishing a darker contrast with the brighter chorus that follows it.
We will use iii only occasionally, although it does appear from time to time. When it does, it usually (although not always) is followed by IV or vi. Weezer’s “The World Has Turned and Left Me Here” (performed in the inconvenient key of F# major) is a good example of how the iii chord is often used.
Note that Weezer plays power chords (chords marked “5,” which means that the root and fifth are to be played without a third), but that doesn’t change the way the chords function. The iii (A#5) seems to point upward at the IV (B5).
The chorus of Taylor Swift’s “Back to December,” which is in the key of D major, also features a prominent iii chord.
Listen to the song and note how dark the F#m chord feels. Due to its dark character, the iii chord is perhaps used more often in the bridges and verses of songs than in choruses, which we expect to be more straightforward. The iii chord can often (although not always, as the Swift example suggests) be used primarily as a change of pace.
Now let’s turn to the viio chord. The circle in “viio” indicates that the chord is diminished. We construct diminished triads by writing a root, minor third and diminished fifth. (A diminished fifth is a half step lower than a perfect fifth.) For example, here’s an A diminished triad. C is a minor third above A, and Eb is a diminished fifth above A.
Here are a few more examples of diminished triads.
|Quick Quiz 3.3
Name the following diminished triads.
The viio chord in major can perhaps best be thought of as a less stable variant of the V chord, since the two chords contain two notes in common. For example, in G major, V contains D, F# and A, and viio contains F#, A and C.
Most of the time, we’ll want to use V rather than viio, although viio can occasionally be an effective alternative in transitional passages or in other contexts where a little instability is effective. The viio perhaps plays a more prominent role in minor keys, and many of the best examples of pop songs using viio are in minor, so we’ll hold off further discussion until then.
How Often Should We Use Each Chord?
When we’re writing songs in major keys, we’ll typically use chords from our palette with about the following frequency, from most common to least common.
I, V, IV, vi, ii, iii, viio
Your mileage may vary, however. Artists like R.E.M. have had success with frequencies that are somewhat different (placing, for example, a heavier emphasis on chords like ii). But the list above provides a reliable starting point. We’ll add more chords to our palette in the chapters that follow.
|Quick Quiz 3.4
Name the notes of the following chords.
IV in F major
Next Chapter: Dominant Seventh Chords
Quick Quiz Answers
D major: I is D, IV is G, V is A, and vi is Bm
A major: I is A, IV is D, V is E, and vi is F#m (remember, F# is the sixth scale degree of the key of A major, not F)
Eb major: I is Eb, IV is Ab, V is Bb, and vi is Cm
Co = C, Eb, Gb
F#o = F#, A, C
Bbo = Bb, Db, Fb. Gross! Note that the third note is not E, even though E and Fb are the same notes at the piano, since a diminished chord calls for a fifth, and E would form a fourth.
IV in F major is Bb major (Bb, D, F).
iii in A major is C# minor (C#, E, G#).
ii in G major is A minor (A, C, E).
viio in E major is D# diminished (D#, F#, A).