It was Cason, along with songwriter partner Mac Gayden, who wrote "Everlasting Love," the Motown-style track that would make Knight a star when it was released in 1967, crossing from the R&B charts to the pop listing and peaking at No. 13 on the Billboard Hot 100.
“Buzz and Mac were country artists, and I was R&B, and so I had to make it more of an R&B song,” Knight told Rebeat Magazine in a 2016 interview. “I practiced and practiced on it -- it was a hard song to sing because, at the time, it was hard to sing a fast song slow. I didn’t sing it the way they had written it. I made some changes to fit my voice, and I didn’t do it note for note. They had the melody going too fast, and it was jamming, it wasn’t doing right, it wasn’t sounding right. So I started what you call a steady step. I start singing a beat and a half: ‘hearts-go-a-stray’ -- like that. It wasn’t like that in the beginning, and I think that’s what got ‘Everlasting Love’ off the ground.”
Knight continued charting songs, including "Blessed are the Lonely" and "Isn't it Lonely Together," but neither reached the heights of "Everlasting." Knight reportedly moved away from music later in life to focus on a job at Vanderbilt University in Nashville as a lab technician, chemistry teacher and member of the grounds crew.
Meanwhile, "Everlasting Love" has proven to be one of the great pop perennials of the late 20th century, having been covered by everyone from U2 to Gloria Estefan, Carl Carlton and Love Affair. Between its various versions, the song has become a Hot 100 top 40 hit in each of the '60s, '70s, '80s and '90s.
"With 'Everlasting Love,' Knight created the blueprint for one of the most famous, most enduring songs to ever come out of Music City," Michael Gray, a historian at the Country Music Hall of Fame and Museum told the Tennessean. "Recording extensively with Mac Gayden and Buzz Cason in the 1960s, Robert was working in integrated bands when it was still taboo to do so in some places. The original version of 'Everlasting Love' is a prime example of the successful musical exchange between black and white musicians during a decade of great racial upheaval and Civil Rights struggles in the South."