A chord is several musical notes sounded together, or in geometry a straight line joining two points on a curve. A cord is a length of string, rope or cable. The vocal cords take the plain spelling, and "strike a chord" takes the H.
The core difference
A musical or geometric term and a physical length of string.
- chord — notes together: a minor chord; a line across a curve: the chord of a circle.
- cord — string, rope, cable: an extension cord, the spinal cord, vocal cords.
The two phrases
Strike a chord takes the H — the image is musical resonance. Vocal cords do not — they are physical bands of tissue, and the frequent "vocal chords" is an error, understandable given that they produce sound.
Where the H came from
Chord in music was originally spelled cord, a shortening of accord. The H was added later by false analogy with Greek-derived words — so the musical spelling is, historically, a decoration that stuck.
Frequently asked questions
Is it vocal cords or vocal chords?
Vocal cords — they are bands of tissue. The chord spelling is musical.
Is it "strike a chord" or "strike a cord"?
Strike a chord, with the H — the image is musical resonance.
Why does chord have an H?
It was added later by false analogy with Greek-derived words. The musical sense was originally spelled cord, from accord.