What Are Chords? 5 Rules to Remember (Chords Explained)

If you’ve been playing guitar for a while, you’ve probably played thousands of chords… but maybe you’ve never stopped to ask:

“Wait… what exactly am I playing?”

In this lesson from my 30 Day Guitar Chord Fluency course, we’re going to make chords feel simple, logical, and repeatable—so you’re not just memorizing shapes, you’re understanding what’s inside them.

By the end of this article, you’ll know:

• what a chord really is,
• what notes make up most basic chords,
• why chords can sound “different” even when they’re technically the same chord,
• and the 5 rules I want you to remember forever.

Let’s dive in.

Jump to Section:

• 1. A chord is 3 or more different notes
• 2. Most basic chords are built from Root – 3rd – 5th
• 3. The root is not always the bass note (Inversions)
• 4. Chords are spelled using every other letter of the musical alphabet
• 5: You can double or omit notes in a chord
• Quick guide: Types of chords
• Practice & Next Steps

Rule #1: A chord is 3 or more different notes

The basic definition of a chord is:

Three or more different notes played at the same time (like a strum) or played in a sequence (like an arpeggio).

So yes—this counts as a chord:

• Strummed: play multiple notes together
• Arpeggiated: play the same notes one-by-one

Example: C major

A C major chord is made of three notes:

C – E – G

You can strum them together… or play them individually. Same chord. Same “ingredient list.”

Rule #2: Most basic chords are built from Root – 3rd – 5th

Think of chords like a recipe. Most of the chords you play early on (major/minor especially) are built from three essential chord tones:

The 3 parts of a chord

• Root: the note the chord is named after
• Third: the note that largely determines major vs. minor
• Fifth: the note that stabilizes the chord’s sound

Rule #3: The root is not always the bass note (hello, inversions)

Here’s where people get tripped up:

The root of the chord does not have to be the lowest note you hear.

When a chord tone other than the root is in the bass, it’s called an inversion.

C major inversions (C–E–G)

• Root position: C is in the bass
• 1st inversion: E is in the bass (the 3rd is in the bass)
• 2nd inversion: G is in the bass (the 5th is in the bass)

Why inversions matter (musically)

Inversions are often used to create:

• tension
• forward motion
• anticipation
• a more “composed” sound than jumping between chunky root-position chords

First inversion chords (3rd in bass) are used for melodic bass lines, parallel motion, or to reduce tension.

Second inversion chords (5th in bass) are mainly used for cadences, passing tones, and pedal points.

Very often I find that the 5th in the bass helps “prepare your ear” for the V chord, which extends the cadence and builds excitement!

For instance, the end of Tárrega’s Estudio in C major uses a C major chord in second inversion (G in the bass) to prepare your ear for the V chord (G major), and then eventually resolves to C major in root position!

Rule #4: Chords are spelled using every other letter of the musical alphabet

This rule is one of the biggest “lightbulb moments” for beginners.

The musical alphabet is:

A – B – C – D – E – F – G (then it repeats)

To spell a basic chord, you use every other letter.

Example: spelling an A chord (letter-wise)

Start on A (root), then skip a letter each time:

• A (root)
• skip B → C (third)
• skip D → E (fifth)

So an A chord is spelled:

A – C – E

Important note: this tells you the letters—it doesn’t automatically tell you whether the chord is major or minor. That depends on the exact spacing (sharps/flats) between notes. But as a starting point for chord building, this rule is gold.

Another example: D chord (letter-wise)

• D (root)
• skip E → F (third)
• skip G → A (fifth)

So:

D – F – A (that’s the spell for D minor)

Rule #5: You can double notes (and sometimes omit notes)

Guitar has six strings, but basic triads have three chord tones.

So what happens?

We often:

• repeat notes (doubling)
• and occasionally leave one out (omitting)

Example: open C major shape

A C major chord is C–E–G… but your typical open C chord might include:

• multiple C’s (octaves)
• multiple E’s
• maybe only one G

That doesn’t make it “wrong.” It’s just how the guitar lays out chord shapes.

If you omit a note…

Most of the time, the note that gets omitted is: the 5th

Because:

• the root tells your ear “what chord it is”
• the 3rd tells your ear “major or minor”
• the 5th is important, but usually the least essential of the three for identifying the chord quality

Quick guide: Types of chords (the emotional snapshot)

In this lesson we also touched on the most common chord “flavors”:

• Major: bright / happy
• Minor: darker / sadder
• Diminished: tense, suspenseful, unstable
• Augmented: spacious, unusual, “outer space” vibe (often used for atmosphere in film music)

Most of what you’ll use early on is major and minor, but knowing the other two exist helps your ear make sense of what you hear later.

Practice: turn these 5 rules into chord fluency

Here are a few simple practice steps you can start today.

1) Identify Root–3rd–5th in every chord you play

Pick a chord you already know (C, G, Am, Dm, etc.) and ask:

• What’s the root?
• What’s the third?
• What’s the fifth?

Say them out loud. Seriously—this helps.

2) Try one inversion

Take a familiar chord and experiment with putting:

• the 3rd in the bass (1st inversion)
• the 5th in the bass (2nd inversion)

Listen for how it changes the “feeling.” Same chord name, different emotional weight.

3) Compare major vs. minor vs. diminished

Play:

• one major
• then make it minor
• then try a diminished version

You’re training your ear to recognize chord color.

4) Spell chords with the alphabet rule

Pick any letter and spell the triad using every other letter:

• A → C → E
• D → F → A
• G → B → D
• etc.

This is one of the fastest ways to stop seeing chords as random shapes.

5) Experiment with doubling/omitting notes

Take something like C major and try:

• leaving out the 5th
• doubling the root
• doubling the 3rd

Then listen: what feels stable? What feels “open”? What feels tense?