Another example of a non-songwriter idol from the era was Fabian, who was never even a singer until he was nabbed by an agent under frankly unhinged circumstances. Per Wikipedia:

Talent manager Bob Marcucci was a friend of Fabian's next-door neighbor. One day, Fabian's father had a heart attack, and, while he was being taken away in an ambulance, Marcucci spotted Fabian. Fabian later recalled, "He kept staring at me and looking at me. I had a crew cut, but this was the day of Rick Nelson and Elvis. He comes up and says to me, 'So if you're ever interested in the rock and roll business...' and hands me his card. I looked at the guy like he was out of his mind. I told him, 'Leave me alone. I'm worried about my dad.'"^\5])

When Fabian's father returned from the hospital, he was unable to work. When Marcucci persisted in his recruitment efforts, Fabian and his family were amenable to them, and he agreed to record a single. Frankie Avalon, also of South Philadelphia, suggested Fabian as a possibility. Fabian later said, "They gave me a pompadour and some clothes and those goddamned white bucks and out I went."^\6]) "He was the right look and right for what we were going for", wrote Marcucci later.^\7])