Chord Progression

Certain sequences of chords sound nicer than the others. Over time, a consensus devleoped to become the rules of chord progression.  The rules arre based on a concept called chord leading - certain chords naturally lead to other chords.

Major chord leading
I can appear anywhere in a progression (any chord can go to I)
ii to I, IV, V, or viio (minor seventh dim)
iii to I, ii, IV or vi
IV to I, ii, iii, V or viio
V to I or vi
vi to I, ii, iii IV or V
viio to I or iii

Minor chord leading
i can appear anywhere in a progression
iio or ii to i, iii, V, v, viio, VII
III or III+ to i, iv,IV, VI, #vio, viio, VI
iv or IV to i, V, v, viio or VII
V or v to i, VI or #vio
VI or #vio to i, III, III+ iv, IV, V, v, viio or VII
viio or VII to i

Common chord progressions
(1) I, IV, V and V7 (C, F, G, G7)
e.g. I-IV, I-V, I-IV-V or V7, I-IV-I-V of V7, I-IV-V-IV

(2) mixing other chords with combination of IV and V
e.g. I-ii-IV-V, I-ii-IV, I-V-vi-IV, I-vi-ii-V or V7, I-vi-IV-V, I-vi-ii-V7-ii

(3) starting with non-tonic chord
e.g. ii7-V7-I, IV-I-IV-V

(4) 12-baror blues progression
I-IV-I-V7-IV-I (C, F, C, G7, F, C)

(5) circles of fifths - each chord is a diatonic fifth above the following chords which makes each chord functionally a dominant for the next
I-IV-viio-iii-vi-ii-V-I (C, F, Bdim, Em,Am, Dm, G, C)