Forgive me if my terminology is not the best.
I've long loved cadences where, in a major scale, a II is played instead of ii.
For instance,
G, A, Bm, C, D, Em, F#dim
rather than
G, Am, Bm, C, D, Em, F#dim
I just don't know if this chord has been given some name (memorable or otherwise). The closest I can call it is a major second chord, or a lydian loaner, or something.
Any info is greatly appreciated.
-Jon