Primary chord
Triad on the I, IV, or V degree of a key (tonic, subdominant, dominant).
What it means
Primary chords are the triads on the first, fourth, and fifth degrees of a key: tonic, subdominant, and dominant. They form the harmonic framework of a key, since with them all notes of the scale can be harmonised. In C major they are the chords C, F, and G.
Musical use
Many simple songs, folk songs, chorales, and blues pieces manage with the three primary chords. Their functions complement one another: the tonic is the point of rest, the dominant creates tension, and the subdominant opens up and prepares the dominant. The most common cadences, such as T–S–D–T, consist exclusively of primary chords.
Primary chords should be distinguished from secondary chords on the remaining degrees, such as the tonic parallel or the subdominant parallel, which represent the main functions but sound softer and less clear-cut. They also differ from secondary dominants and altered chords, which come from other keys or chromatic changes.
Performance practice
Learn the three primary chords in all keys by heart and accompany simple songs with them. Play the changes calmly and evenly and prepare the chord changes before they arrive.