In one of your earliest lessons (Jazz improvising or something), you showed this final cadence, very usual in Jazz endings -it´s actually a kind of “mini coda”, as I understand, because many times is employed after the real “story” ends:
I – (ii V7)bIII – I or
I (ii V7)bVI – I
My question is: how do I functionally categorize these? Is it a subdominant-dominant secondary cadence?
In the first case, I´d say it´s a secondary cadence over a tonic chord (bIII) borrowed from paralel minor. In the second, a secondary cadence over a subdominant chord (bVI) also borrowed from paralel minor.
(in the last phrase of Shadow of Your Smile, one of these (ii V) replace very effectively the main V7 and to me it´s the pinacle of the song. In this case, for me they are not in the role of “mini coda” of course)
I always say to my students: all harmonic gestures came from usage – that´s more important than schoenbergly theorizing about it´s acoustical origins , but in this case I´m really intrigued. To sum up: why the hell does it sound so well???