Chords: basics

In short: A chord arises when at least three notes sound at once. The simplest is the triad of root, third and fifth. Chords form the harmonic foundation of a song.

In more detail: A major triad has a major third, a minor triad a minor third. C major consists of C, E and G.

In detail

• Degrees: In C major the notes C, D, E, F, G, A, B form degrees I to VII, on each of which a triad can be built.
• Main functions: Tonic (I), subdominant (IV), dominant (V). Many songs consist of these three chords.
• Seventh chords: With a fourth note, the seventh, chords sound more tense (e.g. G7).
• Inversions: The notes of a chord can be played in another order.
• Chord symbols: C, Am, G7, Fmaj7 in songbooks.
• Popular progression: I–V–vi–IV (C–G–Am–F) in countless pop songs (tonleitern-dur-und-moll).