To my surprise, the weight of scholarly opinion is that "up to G" comes from
the musical key of G.

 From Jonathan Evan Lighter. The Random House Historical Dictionary of
American
Slang. Vol. 1 (1994) (note the variant following line, 'on the hog' rather
than 'are wand'rers'):

Up in [or to] G [alluding to the key of G in music] superlative; doing very
well; at or to a high point.
1884 Accidentally Overheard, p.15: "The young lady next door .is up in solos
in G."
1894 C. Lawlor & J. Blake "Sidewalks of N.Y." (pop. song) Things have
changed since those times, some are up in "G"/Others they are on the hog.
1894 Harper's (Dec.) 104: "I've got to get a mother; what I mean is a real
way-up-in-G one I mean to say a mother that's out of sight, m'm."
1895 Harper's (April) 786: "You get everything way up in G there, with cakes
on the side.
1895 Townsend, Edward W. "Chimmie Fadden," Major Max, and Other Stories. The
American Short Story Series, Vol. 82. p.5 "Say, I knowed  ye'd be paralyzed
wen ye seed me in dis harness. It's up in G, ain't it? Dat's right."





----- Original Message ----- 
From: Michael Cassidy
To: [log in to unmask]
Sent: Friday, February 25, 2005 9:51 AM
Subject: Re: Musical Sidewalks of New York


I still agree with my brother its more likely 'g' for gaol for Sing Sing.


On Feb 24, 2005, at 12:34 PM, [log in to unmask] wrote:



Things have changed since those times, some are up in "G"
Wild guess:  Key of G.  Better than G train, at least.      Christopher Gray


Jazz is freedom. - T. Monk