I just got a copy of Soundings 9 via interlibrary loan to take another look at Gavin Bryars’ score for The Sinking of the Titanic.
Inside it I found this inscription:

On a hunch, I looked up Lou Harrison, and sure enough his partner’s name was William (Bill) Colvig.
The bookplate says it’s from the collection of Robert E. Brown, who is credited with, among other things, introducing Gamelan music to America.
Harrison was of course influenced and inspired by Gamelan music.
O.
M.
G.
I’m touching a book Lou Harrison (probably) touched!
My daughter informed me I am “fangirl”ing.
Guilty as charged.