What Is a Chord?
Several notes played at the same time are called a chord. How triads are built, how many notes a chord needs, and where 2-note "chords" fit in.
🎯 Practice it: Chord Quality →What Is a Chord?
When several notes are played at the same time, that combination is called a chord — the basic building block of harmony. A chord is what turns a single melody into full, rich-sounding music.
So far we've played one note at a time. Now listen to scale degrees 1, 3, and 5 played together:
That rich, full sound is a chord — specifically a triad: three notes stacked a third apart.
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What Is a Chord?
When several notes are played at the same time, that combination is called a chord — the basic building block of harmony. A chord is what turns a single melody into full, rich-sounding music.
So far we've played one note at a time. Now listen to scale degrees 1, 3, and 5 played together:
That rich, full sound is a chord — specifically a triad: three notes stacked a third apart.
The Major Triad
The chord you just played (1-3-5) is called a major triad. It's the most fundamental chord in music.
• 1 = Root (the foundation)
• 3 = Third (determines major/minor)
• 5 = Fifth (adds stability and fullness)
This is the 'home' chord
Melodies resolve to it. Songs end on it. It's the destination in chord form.
How many notes does a chord need?
A basic triad is three different notes — root, third, and fifth. Stack a fourth note on top (a seventh) and it becomes a four-note chord, which you'll meet in later lessons. Doubling a note in another octave — say, two roots — doesn't add a new ingredient; it's still the same three notes, just voiced with extra weight.
Can a chord have just two notes?
Strictly, no — a chord needs at least three different notes to show whether it's major, minor, diminished, or something else. Two notes played together is an interval, not a full chord: without a third note, there's no way to tell major from minor. That said, musicians casually call some two-note shapes "2-note chords" all the time — a guitar power chord is exactly that, a root and a fifth with no third — so the loose usage isn't wrong, just worth knowing it's technically a dyad. Our lesson on intervals covers how musicians name the distance between any two notes, which is the same vocabulary that describes a two-note "chord."
Build More Triads
Listen to triads built on different scale degrees:
The IV chord (4-6-8)
The V chord (5-7-9)
These three chords – I, IV, and V – are the most important chords in any key. They're the foundation of most songs you've ever heard.
Chords in Your Music
Most pop songs use only 3-4 chords. The I chord (1-3-5) appears in virtually every song.
Listen for the I chord in songs you know — once you recognize it, you'll hear it everywhere.
Coming up: Happy and Sad — the difference between major and minor chords, and why one sounds happy while the other sounds sad. For the full theory on how triads are built and named, RealMusicTheory's guide to triads goes deeper.