Secondary dominants can add an interesting harmonic color to a musical piece and can be used to embellish many chord progressions used in classical, Jazz and popular music. Let's see some common chord progressions that we will transform using secondary dominants...
The very common II - V - I progression:
Substitution of the II degree chord (Dm7) by the D7 secondary dominant:
The III -VI - II - V progression:
Substitution of the III degree chord (Em7) by the E7 secondary dominant, the VI degree chord with an A9 and the Dm7 with a D7: