Chord substitutions where the bass falls or rises a minor second, or falls a tri-tone plus a minor second, or where inner parts move chromatically by half steps, are effective in projecting splashes of color and suggesting deep feeling. Though they entail chromatic alteration, they tend to fall easily for the hands of keyboardists. And bass players love them!
In this chapter we mainly concentrate on two “dominant” progressions: (1) progressions down a fourth; and (2) secondary (or applied) dominants. From your music theory, you may have learned about V of V chords (an example of a secondary dominant). Secondary dominants usually introduce chromaticism, and often propel the music forward strongly.
Play God is so Good and AmazingGrace in various keys using a lead sheet and a Roman Numeral chart. Many of the same progressions occur.