A chord progression is a sequence of chords, creating a recognizable sound. The chord progression is the element of a song that gives direction to all the melodies.
For centuries, composers have discovered certain chord progressions that you can hear in many songs today. Have you ever had the following feeling? A song starts, and you can already predict what the melody will be. This is because your ears recognize a certain chord progression that they already heard before.
In music theory, chords are indicated by the following Roman numerals: I, II, III, IV, V, VI, VII. These numerals refer to notes on a musical scale. For instance, the Roman numerals accompanying the C major scale are:
As you can see, every letter on the scale is connected to a Roman numeral. So, in case of the C scale, the I chord (or tonic chord) indicates the chord that is based on the C note; the II chord indicates the chord that is based on the D note; the III chord is the chord based on the E note; et cetera.
Moreover, in music theory, we have special names for the chords of the diatonic scale. Here are the most famous ones. We strongly recommend you to remember:
- Tonic chord (T) – chord, based on the first (I) scale degree.
- Subdominant chord (S) – chord, based on the fourth (IV) scale degree.
- Dominant chord (D) – chord, based on the fifth (V) scale degree.
Using the numerals as symbols, we have a way of notating chord progressions. What are the most common chord progressions? Here are some examples:
- The I-IV-V (or 1-4-5) progression. The best examples are found in rock ’n’ roll songs.
- The II-V-I (or 2-5-1) chord progression. Check out this explanation on the 251 chord progression.
- The I-V-VI-IV (1-5-6-4) chord progression, used in Pink’s “F**king Perfect.”
- The I-VI-V (1-6-5) chord progression, used in Justin Timberlake’s “Not A Bad Thing.”