There are many different types of piano chord progressions, but they can simply be divided into major chord progressions, minor chord progressions, and mixed chord progressions. The rules for chord progressions are dictated by music theory, particularly chord progression theory. These rules can be broken by musicians wishing to create interesting and original piano chord progressions, but are generally best adhered to. In any scale, the I chord can go to any other chord, the iii chord can lead to the vi chord, which can lead to the ii or IV chords. From the ii or IV chords, the progression should go to the V or vii chord before reaching the I chord again.
Most common piano chord progressions can be understood by looking at music theory. Each note in a scale is referred to by a number between one and seven, which in chord theory are often displayed as roman numerals. The C major scale, C, D, E, F, G, A, and B, can be numbered one to seven in that order. Chords in the first (I), fourth (IV), and fifth (V) positions are always played as major chords, and ones in the second (ii), third (iii) and sixth (vi) positions are always played as minor chords. The seventh (vii) is always a diminished chord.
Major chord progressions are one of the most basic piano chord progressions. These utilize the major chords, which are the ones occupying the first, fourth, or fifth positions in any scale. The I chord can lead to any chord in the scale, and most chord progressions should start from this chord. Assuming the chord progression went to the IV chord next, it would then be able to move to the V chord before going back to the I chord. This is the most basic of the major piano chord progressions.
Minor piano chord progressions work in essentially the same way, except they use the minor chords from positions ii, iii, and vi of a scale. They can also use the I chord and the V or vii chord to get from one chord to another. Starting with the I chord, the progression could move to the iii chord, then the vi chord, and finally the ii chord. From this position, the progression has to move to the V or vii chord before either going to the I chord again or back to iii.
Other piano chord progressions can use a combination of minor and major chords to create a more interesting sound. Still other types of chords, such as seventh chords, can also be used to create new types of effect. It is also worth noting that musicians often don’t adhere strictly to the rules imposed by chord theory.