At the risk of being a bit predictable (and also to get it out of the way early), the first double neck guitar is the Gibson EDS-1275, forever to be known informally as the Jimmy Page model. 12 string on top, 6 string on the bottom, and a whole lotta love in between. If by love you mean mahogany.
When I was a kid, a local music store had an Ibanez copy of this model. I used to stare at it for what felt like hours but never plucked up the courage to ask to play it. Add that to my list of guitars I’ll treat myself to if I ever get insanely rich.
CLICK HERE to buy the Gibson EDS-1275 from Music123
or CLICK HERE to buy the Epiphone version.
Random awesome double necks on eBay: