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Beginner · Foundations

What is a chord?

A chord is the starting point for almost everything in harmony. Here is what chords are, how they are built, and why understanding them changes the way you hear music.

The simple answer

A chord is two or more notes played at the same time. In practice, most chords you will encounter are built from three notes — a structure called a triad. Triads are the foundation of piano harmony, from basic pop to gospel to jazz.

If a melody is a single person talking, a chord is a group of people speaking in harmony. The notes you choose and the gaps between them determine whether the chord sounds happy, sad, tense, or resolved.

Root, third, and fifth

Every triad is built from three specific intervals measured from a starting note called the root:

RootThe starting note — gives the chord its letter name (C, G, F, etc.)
ThirdThe note 3 scale steps above the root — decides if the chord sounds major or minor
FifthThe note 5 scale steps above the root — anchors the chord and gives it stability

C major uses the notes C, E, and G — root, third, fifth from the C major scale. That combination is one of the most common sounds in all of Western music.

Major vs minor: one note changes everything

The difference between a major chord and a minor chord is a single half-step on the third. Lower the third by one fret (or key) and the chord flips from bright to dark.

C major vs C minor
CC – E – Gbright, stable, confident
CmC – E♭ – Gdarker, emotional, serious

Play C, E, and G together on your keyboard — that is C major. Now move the E down one key to E♭. Same chord, one note different — that is C minor. The change is small; the feeling is dramatically different.

Why chord names matter

When someone says "play a Cmaj7" or "the chorus is I–V–vi–IV," they are describing harmony using chord names. Names let musicians communicate quickly, read sheet music, follow lead sheets, and understand what they are playing beyond just shapes and muscle memory.

If you have ever played a chord without knowing its name, you were relying on pattern alone. Knowing the name connects the pattern to a concept — and that connection makes everything else easier: transposing, substituting, arranging, composing.

Common symbols you will see
CC majorroot position major triad
CmC minorlowered third
C7C dominant 7thadds tension
Cmaj7C major 7thlush, open

How ChordBeam helps you connect names to playing

ChordBeam listens to your MIDI keyboard and shows you the chord name, the individual note names, and which note is in the bass — all in real time. Instead of having to guess or look up a chord after the fact, you see it identified the moment you play.

This is especially useful for self-taught players who know shapes but not names. Play a chord you already know, see its name appear, then read about that chord family in the Chord Library to understand the theory behind the shape.

Apply what you learned

Connect your MIDI keyboard and use ChordBeam to hear these concepts in real time as you play.

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