If you want to get a solid grasp of chord theory, you have to start from the beginning. A great starting point is with the Introduction to Chords. Chords are built on specific spaces or intervals in a musical scale. In Western music the smallest interval is the semitone, that is the same as one key distance on the piano or one fret on the guitar. Before we start analyzing multiple notes it is best to learn the basic sounds of each main interval in the chromatic scale.
When studying music theory it is always helpful to have a keyboard or piano accessible. Regardless of your main instrument, a keyboard really helps visualize what you are learning. A cheap ancient Casio or Yamaha at a secondhand store or a small MIDI keyboard to plug into music apps.
As long as it has at least two to three octaves and sounds ok, it will do the job. For each interval example play along and repeat it and practice it. Eventually take the lessons learned over to your preferred musical instrument and get to know that note layout better. With enough practice you will start catching random intervals of the music you hear throughout the day!
Let’s start with the main intervals of the chromatic scale:
(If it is helpful to put tape with note names on your keyboard, that is fine. Whatever you need to cement the rules and sounds into your head the better.)
Remember the notes with slashes are enharmonically equivalent. The different names depend upon the key and situation the note is in. Intervals are not just defined by their number distance; they also have a quality.
These qualities are called perfect, minor, major, augmented, and diminished. We have picked the C scale above as that is a commonly used scale, but the quality of the interval based on the semitones apart are the same for each scale. You will be able to quickly see and hear this if you have a keyboard or piano at your disposal.
The first note C, in relation to itself is of course perfect unison. There is no difference in sound when you play to C notes.
Major & Minor Second
The major second interval is two semitones apart giving us C to D. Some great ascending examples are; the second two notes of Happy Birthday, and the start of Christmas classics like Rudolph the Red Nosed Reindeer and Silent Night.
Moving down from D to C we have examples like Mary Had a Little Lamb and also the start of Yesterday. Remember that while we may be using only C as our sample key, this will work across all other keys. When you play some of these song examples, they may sound a little off and that is likely from them being in the wrong key. Try other 2 semitone intervals with other notes on the keyboard, both ascending and descending. Eventually you will find the right key of the song you are attempting.
Now play C followed by C# repeatedly, hopefully you recognize the theme from Jaws. By moving one semitone up in the scale we have the minor second interval. Because you are moving up the scale it is an ascending interval. Other examples of ascending minor seconds are the very first two notes of the Pink Panther Theme and also the beginning of The Long and Winding Road.
Now a descending interval has a different sound. Technically when descending we are playing the inverse of the minor second. That’s the thing with music theory, it can get really bulky and awkward fast. It’s more important to focus on recognizing the sound rather than the technicality of the name. One of the most popular descending C# to C songs is the first two notes of Joy to the World and Für Elise.
Major and Minor Third
When moving four semitones we get the major third with the notes C-E. Of course we have a Beatles song as an example and that’s the first two notes of “Can’t Buy Me Love”. Other ascending examples are “When the Saints Go Marching In” and “Kumbaya”.
Now descending from E to C we have such notable examples as the first two notes from Beethoven’s 5th Symphony and the kid’s song “Shoo Fly”!
By moving three semitones up we have the minor third, the notes C-D#/Eb. Two great examples of this are the first two notes of the songs “Hello Goodbye” and the signature riff of “Smoke on the Water.”
Of course when descending from D#/Eb to C we have the popular holiday tune “Frosty the Snowman”. Another couple great examples are the nursery rhyme “This Old Man” and The Beatles classic “Hey Jude”.
Perfect Fourth and Diminished Fifth/Augmented Fourth
Five semitones bring us to the perfect fourth, moving from C to F. If you play this, you will immediately recognize “Here Comes the Bride” (which of course is not the real title). You will also use this interval when you sing “Amazing Grace” and “Auld Lang Syne”.
Diminished Fifth/Augmented Fourth
Now this interval is the start of the tritone, those dreaded and evil musical notes. If you play six semitones up from C, which is F#/Gb you will hear a dissonant sound. These are intervals that lead to a lot of tension in music which explains why they have such a weird reputation. The note F#/Gb can be called a diminished fifth as it is one half semitone below the fifth G. And it can be called an augmented fourth as it is one semitone above the fourth F.
Two very popular ascending examples are “Maria” from the musical West Side Story and the start of the “The Simpsons Theme”. Descending from F#/Gb to C we have a not so pleasant tone, one that it is interspersed among many heavy metal heavyweights like “Enter Sandman” and “Black Sabbath”.
By moving seven semitones up the scale we have C-G, the perfect fifth. One of the most pleasant sounding intervals for the human ears. As we expand into learning our chords and songwriting, we will see this interval and chord change very often. Ascending examples are “Baa Baa Black Sheep”, “Twinkle, Twinkle”, and “The ABC’s” (quick fact, all of them are the exact same melodies!). And we can’t forget the first two notes of the “Star Wars Theme”!
When descending from G-C we get popular tunes like “The Flintstones Theme” and “The Superman Theme”.
Major And Minor Sixth
Moving nine semitones up from C-A we have the major sixth. Many of us have heard that interval since we were children from the “Hush Little Baby” nursery rhyme. Another weathered tune with this ascending interval is “For He’s a Jolly Good Fellow”.
When we play A-C, we hear the interval sang by Patsy Cline in the country standard “Crazy”. That same descending interval has been around since the 19th century spiritual “Nobody Knows the Trouble I’ve Seen”, the very first two notes on no-body.
Eight semitones up we move from C-G#/Ab with the minor sixth. The initial notes of “Because” and the third and fourth notes of the ragtime classic “The Entertainer”.
When descending from G#/Ab-C we find that in the “Theme from Love Story” and later in that song look for the minor sixth again, but this time it is ascending.
Major and Minor Seventh
Eleven more semitones later we have C-B the major seventh. This is heard in the 80’s hit “Take On Me” and on the more recent hit “Don’t Know Why”.
When descending from B-C we have songs like “Have Yourself a Merry Little Christmas” and “Immigrant Song”. Actually in that song, Led Zeppelin plays the octave and then the descending major seventh.
The minor seventh is ten semitones above giving us C-A#/Bb. Ascending this interval is the famous beginning of “Star Trek” and “Somewhere” another great tune from West Side Story.
Descending the minor seventh is quite the jump, present in jazz standards like “Watermelon Man”. This is not a common interval to run into.
Twelve semitones later we come to the next C, one octave up. Besides the song mentioned above we also have the first notes of “Somewhere Over the Rainbow” and “Singin’ in the Rain”.
Moving backwards we can hear the “Doogie Howser Theme” and especially in the beginning of the classic “Willow, Weep for Me”.
Of course there are so many more examples and that’s part the fun now. There are a variety of videos out there and pages dedicated to interval examples and ear training. There are also apps and software out there designed to help you study. The more you practice the easier it will be to just listen to a tune or a bandmate and know the interval they are playing.
Power Chords / Double Stops
The next step after learning your intervals is to start putting some notes together and, in this section, we will stick with two notes at a time. They can be known as double stops or power chords, but they technically are not chords being made up of only two notes. One rare term is to call them dyads (with three notes it’s a triad).
When you think about woodwinds or brass, they can only play a single note at a time and in the various intervals we discussed above. Once we get into some string instruments like violin and cello you can start playing two notes at a time. Double stops are also common among mandolin players in bluegrass music. And even though the guitar has six strings, a very basic technique of playing only a few strings at a time is very common.
When we play certain string instruments it is impossible to hit all the notes and to make actual chords in most cases. Instead we substitute two of the notes to get close to the sound. In some cases the remaining notes are played by other band/orchestra members or even potentially in the vocals. The most common two notes played are first and the fifth. The “chord” C5 is made up of the notes C and G, the root and the fifth. Remember these two notes really compliment each other and are what power chords are created with.
If a guitar has more than enough strings to create a lot of chords why limit it by only playing a few? Mainly it is done to achieve a specific sound of the genre you are playing in. Power chords are very simple and are often associated with poor playing ability.
They can have the reputation of musicians who never bothered learning real chords and just stuck to a couple notes. After all power chords are made up of a very simple root, fifth, and the octave. This gives the “chord” a very powerful feel and sound. Yes in some cases power chords are from lack of training, but in reality, it is mostly to achieve a specific goal. If a song you are playing should whip an audience into a frenzy than power chords are what you need.
Major chords are often used in rock and pop and upbeat tunes, to make it even more rocking we play just the power chord. The power chord is often played on the lower bass strings of the guitar and can give the music a drive.
Depending on the level of distortion they fit perfectly in punk and heavy metal. Technically when adding distortion and effects it layers your sound so more than just the root, fifth, and octave are present. That is actually diving into some serious acoustic science for just a “simple” power chord!
To make the power chord even more powerful and deep sounding, musicians in these genres often use drop D tuning (where you tune your low E to D). This makes playing your root, fifth, and octave even easier! They can also make great drones; some death metal type groups make their musical living with two note drones. Simple mixtures of notes can be layered into complex soundscapes.
So in reality playing power chords on your guitar is not about technical skills, it is all about a certain sound and emotion. If you are a musician and you like the genres of punk or metal stick to simple power chords and put your focus into your effects and distortion to fine tune your playing. The root and it’s fifth will always have a place in many tunes and genres.
So far, we have learned how our intervals sound and put two notes together, now we get into real chords. By definition a chord must have at least three degrees of a musical scale. The first chords we will learn are called major triads, a triad being a set of three notes stacked on top of each other. Remember with power chords we made C5 with the root and the fifth, now to get a regular C major chord we will add one more note.
C D E F G A B C
A major chord or triad is made up of the root, major third, and the perfect fifth. This can be labeled as 1-3-5 or R-3-5 (r for root). If you recall the major third is four semitones up which is the note E. The C major chord is made up of C-E-G, if you have a keyboard in front of you give it a play. As long as you know your scales finding the major chord is always easy. The major triad ALWAYS follows the formula of a major third in the first interval and a minor third in the second. The G Major scale;
Gives us the G major chord of G-B-D. B is a major third away from G and D is a minor third from B. The major chord itself has such a stable and consonant sound that it makes up most of the chords used in popular music.
Rock, pop, folk, punk, in some cases they use nothing but major chords in their songs. One of the most popular chord progressions is simply three major chords. The most pleasant intervals we heard earlier consist of the perfect fourth and perfect fifth. Thousands and maybe more three major chord songs consist of the first, fourth, and fifth of the key. The standard 1-4-5 progression! As you study more music theory it will all start to come together in a bigger picture.
One common aspect used with major chords is what’s called inversion. The C major chord is often expressed as the root position C-E-G, the C is the root and also in the bass. However, it can also be played as E-G-C, and when the third E is the bass note it is the first inversion. If played G-C-E and the fifth G is the bass, then it is the second inversion. Go through the rest of your major scales and pick out the major chords and inversions. Try not to initially look other inversions up, find them on your keyboard first!
Minor triads are the opposite of major triads. Recall major triads are a major third and a minor third of three stacked notes. A minor triad is a minor third and then a major third apart. Perhaps read that a couple times to make sure you got it! Which means the notes of C minor (Cm) will be C-Eb-G. A simpler way is to say minor chords are the root, minor third, and perfect fifth of the scale. Basically when you have a major chord you just flatten the middle note by a half step to get the minor.
Of course like major chords, minor chords also have inversions. The first inversion of Cm would be Eb-G-C and the second inversion G-C-Eb. They work in the same fashion. That simple change of flattening the third gives the chord a completely different feel from the major.
Minor chords give music a dark, sad, or melancholy feel. They still have a stable sound and also do not require resolution; you can start and end a song on a minor chord. If you were writing a hard rocking victory song you would use major chords, if you were writing an epic fantasy tune you would likely use minor chords.
Many chord progressions in most songs are predominantly major chords with some minor chords thrown in. Most all songs follow very strict and repeated patterns, the audience of western music knows what it likes!
One factor to keep in mind about chords is that on many instruments the notes repeat. For example you have three notes in a major and minor chord, but six strings on a guitar. In cases like this, you just have to play multiple notes from the triad.
The basic G major chord on the guitar has the notes GBDGBG. So when you see many strings on an instrument don’t be confused, a triad will only have three notes. Ironically when we get to more complicated chords it can cause problems for small instruments. On a four string mandolin or ukulele you have to really fake the chords with a lot of notes.
We have mentioned how the power chords, major chords, and minor chords are stable. The next chords we will be discussing are the augmented and diminished chords. They are also triads, three stacked notes, just like the major and minor.
As you will see the big difference is how unstable the next chords can be and how they always want to resolve to a major or minor chord. Take extra time to learn all your triads in each key and scale, as later it is these triads that we build on to make more complicated chords. Try to put the computer and all devices away and on your keyboard or chosen instrument, quiz yourself of intervals, power chords, and your first triads. With practice music theory is no big deal!