The progression between subdominant and dominant immediately defines the key of a piece, because these are the only two major diatonic triads that are related by a major second. It is partly for this reason that the progression IV-V-I is considered by many to be one of the fundamental progressions in tonal music. If you include this progression in your own work, however, you have to be careful to avoid the parallel fifths that occur in the second example below.
The example below shows a simple cadential progression with IV preceding a perfect cadence. Much more common than this is the progression ii-V-I. ii and IV share all but one note so they are closely related to each other, and in fact some textbooks consider ii6/5 (a first inversion supertonic seventh chord) to be a subdominant chord with an added sixth.
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