“I’m a Believer” topped the charts in numerous countries — including the U.S. and the U.K. — and stayed at the top of the Billboard Hot 100 for seven weeks. But any music fan checking the charts at the time would also see that halfway down the chart was Neil Diamond himself, whose budding solo career was receiving far less attention.

At the same time he was commissioned to write for the Monkees, Diamond was trying to launch himself as a performer under his own name. His recording career began in 1965, a year before the Monkees’ “I’m A Believer” was released, when he signed to Bang Records. The following year Diamond released his debut studio album, “The Feel of Neil Diamond,” and three singles: “Solitary Man,” “Cherry, Cherry,” and “Oh No No.” Though all three of the singles charted, none broke the top five of the Billboard Hot 100, while “The Feel of Neil Diamond” languished on the Billboard 200, peaking at No. 137.

But while some artists might have been frustrated by being overshadowed by their peers, Diamond himself has claimed that he was overjoyed by the Monkees’ success with “I’m A Believer.” “I was thrilled because, at heart, I was still a songwriter, and I wanted my songs on the charts,” he told Mojo (via American Songwriter), later adding: “But the head of my record company freaked. He went through the roof because he felt that I had given No. 1 records away to another group. I couldn’t have cared less because I had to pay the rent, and the Monkees were selling records, and I wasn’t being paid for my records.”