Hi,
I didn't get around to writing this before - Equinox is indeed in C#m
originally. Or Dbm if you will. To me, realizing just how free Coltrane
is when playing in an "unusual" key like that is a lesson unto itself.
Regarding keys, I think it's a great exercise to play any tune in
multiple keys. Bill Evans reportedly took tunes through all keys when
practicing; in many cases, I've found much better keys than the usual
ones when I do this. Some "standard" keys just don't fit so well on the
guitar, especially if you want to do a chord melody thing. On the
latest issue of Acoustic Guitar magazine, Earl Klugh talks about this
thing.
All the best,
Petri
www.petrikrzywacki.com