Think Disco or early Hip Hop DJs invented mixing and crossfading? I thought the same thing, until I read about this wondrous device.
It's called the Chronophone, and it was invented in 1910 by French engineer Leon Gaumant to sync sound and film when the length of one gramophone simply wasn't enough.
It's capable of crossfading and mixing via two platters, with the sound pumped out via "twin gramophones, driven from a common electric motor between them. An air hose goes to each valvebox from the control valve just under the air pressure gauge...this control valve allowed the operator to crossfade between the two gramophones."
I wonder what people would have thought about scratching records in 1910?
Link --via Gizmodo