The tune, as near as I can tell, is a reharmonization and contrafact on
"Gee, Baby, Ain't I Good to You." The following progression appears in
the A section:
G7SD Db7#11 | C7alt
and then a few bars later:
F7SD B7#11 | Bb7alt
As near as I can tell from the melody and from listening, the "SD"
chords are identical to what I'd call an alt chord or #9#5 chord. Does
anybody know what the "SD" means, and how I would treat it differently
from an alt chord?
I'd think it was Swallow's way of notating an alt chord, except that he
uses the standard alt notation in the very next bar. It might mean
"secondary dominant" or "substitute dominant" or even "subdominant", but
none of those explain the alterations (and "subdominant" makes no
sense).
Any ideas?
HP