The Weltmeister® Basset 1, sometimes referred to as the Weltmeister® Combo Bass, was the first keytar! This rare "Cold War" electro-mechanical keyboard instrument was made from 1963 to 1969 by accordion manufacturer, Weltmeister, in East Germany. It was practically impossible to get one in the US.
The battery-powered Basset 1 was popular in the 1960s and early 1970s with East German dance bands. Its mechanical piano action was derived from its big brother, the Weltmeister® Claviset. Pressing a key causes the lip of a rubber disc to pluck the tine. When the key is released, the sound is stopped by a foam damper. A warning label in German, Cyrillic Russian, and English warns of "danger of life" if you connect it to a radio or an amplifier with AC-DC!