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.
with a 7th added.