I don't get the second half of Corwiniod post in this thread. So If anyone could help me what he means that would be great.
What specifically don't you get (to save me the trouble of explaining all of it)?
i'm guessing you mean secondary dominants? that was what his second post was mainly about. A secondary dominant chord is a the V if that chord was seen as the tonic. So for example, looking at the ii V I progression, in the key of A major. We have bm E A. Now, if we wanted to use a secondary dominant of our V chord the E, we take E and see what chord is the V of E major: B. So now we could have a progression B E A, or V/V V I (read V/V as "five of five"). another example in A: I V/vi vi would be A C# f#m.
Thanks that helped a lot.