I don't know much about doign circuits (vague memories from high school), but I'd like to learn more, with the goal of making instruments.
Beginner-level stuff. I'll put notes on these if/when I've read them.
Make: Electronics: Learning Through Discovery, by Charles Platt
Handmade Electronic Music, by Nicolas Collins
Make: Analog Synthesizers: Make Electronic Sounds the Synth-DIY Way, by Ray Wilson
Practical Electronics for Inventors, by Paul Scherz
Complete Electronics Self-Teaching Guide with Projects, by Earl Boysen & Harry Kybett
The Electronic Musical Instrument Manual, by Alan Douglas &
About internals of old organs. Would be insteresting for the mechainal and valve stuff.