II-V-I progression (idea)

The II/7b-V-I progression was used at great length by Bach , who I think may well have pioneered it. It has the advantage of combining the 'secondary dominant chord' with a seventh. Although this discord was revolutionary at the time, it was soon widely adopted by Baroque composers. Example: (in the key of C )

  II/7b                         V                          I   
 
F# A C D            ->       G B D           ->        E G C
This is the  2nd          This is the root       This is the 2nd 
inversion of the          of the Dominant.       inversion (b) of the root. 
supertonic chord
with a 7th added.