And also, the tolerances in Synthesizers are actually fairly small and idiomatic synths use quite a few relatively obscure parts i.e. How many introductory electronics books discuss OTAs in any detail( for a slightly terrible example)?
I already know, however it's not easy to find out in one resource: The application for music is sufficiently obscure (Analog synths require much more coaxing than (say) a guitar amp) to warrant dedicated discussion.
You are looking for an "introductory electronic book" that discusses the types of circuits that are used in analog synthesizers. Further, those discussions should be accessible (understandable) to someone with little or no prior understanding of linear circuit theory.
Is that a correct reading of the thing you are seeking? If so then I would start with something like the Sam's OpAmp circuits book. If you aren't put off by mathematics, and your original message suggested you were okay with that, then "The Art of Electronics" (Horowitz and Hill) the first four chapters cover pretty much all of the information you need to know to read any of the schematics on the Moog schematics web site. Both books discuss filters, VCOs and VCAs, and transconductance as well.
As for precision, typically analog synthesizers are not nearly as precise as you might imagine. Like many instruments they were made to have a quality sound which may or may not be strictly accurate in terms of musical representation. One of the nice things about the Moog Model 15 was that you could tune it to different types of scales. You do want thermally stable circuits so that you aren't re-tuning all the time, but setting up in the studio I would typically use anywhere from 5 to 20 minutes with the 'high C' (1046 Hz) signal reference to tune in the various oscillators and amplifiers to get a nice 0 dB signal level at the final output and with the half dozen or so oscillators tuned to match frequencies. Not at all like a "modern" keyboard where you turn it on and blam! you're ready to play.
If I am still misunderstanding what you're asking I would like to understand that. You wrote "The application for music is sufficiently obscure ..." which sounds like you are looking for a specific tie into music in general. However the tie into music is, for the most part, entirely incidental to the mechanics of how these things are built so typically references cover the fundamental properties of these circuits without calling out their musical application which is seems to me to be fairly obvious once you know the fundamentals.