Hawaiian guitar

It became known as the “Amway of Hawaiian guitar,” encouraging its 200,000-some alumni to buy studios and sell materials themselves.

As well as the budding pop groups, Ken catered for Hawaiian guitar groups, folk acts, ranting political singers - and anyone else who was prepared to pay £15 to record there.

"I just thought, 'Man, I love the sound of a Hawaiian guitar,' and some great old songs have it on it, so I just bought one," he said.

Their mother, a waitress, played the Hawaiian guitar, while their father worked at a Whitewater service station where the radio was tuned to country and western, pop and, on Saturday nights, the WGN “Barn Dance.”

His father, an accountant and businessman, played Hawaiian guitar and accordion.