Has anyone assembled a list of some known early commercial releases of electrical recordings, 
specifically examples of the different systems? For instance, what were the earliest licensed 
Western Electric examples? What about the optical-recording systems -- there was the Hoxie system 
and wasn't there at least one other one? Were there other electro-magnetic cutters aside from 
Western Electric, am I imagining things or did I read once about an electro-optical-magnetic cutter 
(something somewhat similar to a light valve moving a cutting stylus based on soundwaves converted 
to electrical-lightbulb energy)?

Also, is there definitive documentation as to when the first multi-microphone recordings took place? 
I know there were mechanical multi-horn systems, so the idea of mixing sound sources into one 
cutting channel was known before electrical recording too place, but were there multiple-microphone 
recordings right from the get-go or did electronic signal-mixers evolve?

-- Tom Fine