Robert Conrad "Robb" Flynn is the lead vocalist and rhythm guitarist for the heavy metal band Machine Head. He joined the thrash metal band Forbidden ( originally Forbidden Evil), while in his graduating year at American High School. 16 Aug It's taken sixth attempts but climber Neil Gresham had finally conquored Forbidden Head, in Pembrokeshire, the first person ever to make the. Otherwise, the operation might return responses such as Not Found and Forbidden. To use this operation, you must have permissions to perform the.