"Everlasting Love", written by Mac Gayden and Buzz Cason, has become one of pop music's most durable songs, having been reinterpreted by numerous artists across decades since its 1967 debut. Its unusual structure – a single opening verse that never returns, a brief ad-libbed bridge, and an extended chorus that changes lyrics on repeat – has proved remarkably adaptable to different genres and eras, which the article credits for its enduring appeal to performers.

The song was originally written for Robert Knight, whose 1967 version reached number 13 in the US. British group Love Affair took it to number one in the UK the following year, using only lead singer Steve Ellis alongside session musicians, with future star Kiki Dee among the backing vocalists. Carl Carlton's 1974 version became the biggest US hit at number six, Rex Smith and Rachel Sweet had a minor duet hit in 1981, Gloria Estefan reached the American Top 30 in 1995, and U2 recorded it as a B-side in 1989, earning significant rock radio airplay.