A custom font by Chermayeff & Geismar, hand-made for their own use [CGH] in 1960 or earlier. Appears under the name Electric Circus in New Alphabets A to Z (1974)
There is a poorly drawn digital version by Jason Fagone (Soup Type, 1997).
Contributed by Studio Het Mes
Contributed by Stephen Coles
Contributed by Steve O Connell
Contributed by Florian Hardwig