The tritone substitution, the substitution of II7 for V7, and the III–VI–II–V extension can be combined in different permutations to produce many different variations on the same basic progression—e.g.
A variety of harmonic techniques can be employed to create multiple versions of a common progression, including the tritone substitution, II7 for V7, and the III–VI–II–V expansion, which can be rearranged in different ways to produce distinct variations.