Unchained Melody was a smash hit love song right from the beginning. Written for a movie released in January 1955, it was covered by multiple artists within the same year and at one point during 1955 was in the US Top 40 with 4 different recordings by 4 different artists all at the same time. It was just as popular in the UK. Since then, it has proved a continuing favourite, with new versions and different artist recordings hitting the charts many times over the years.

There are many variations in the various recordings, from a big sound with a full orchaestra & chorus to a tiny intimate sound with a single voice & solo guitar or piano. However there are similarities across the many versions also. Early versions all followed a 4/4 time signature, with a 12/8 or 6/8 time signature taking over in popularity in the 1960s onwards. The gentle melody usually stands out against repetitive chords or arpeggios up and down. The same chord progression is followed by all.

The creation of Unchained Melody was a joint effort, with Alex North composing the music and Hy Zaret composing the lyrics. The song received its name from the movie it was written for, a prison movie called Unchained. For me, learning this context gave the lyrics of the song new depth, meaning, and emotion. IMDb summarised the movie Unchained as follows: "A convict in a medium-security prison is torn between his need to finish his sentence and get back to his wife and family, and his desire to escape the confines of prison." Unchained Melody is sung with an unsteady beat by a prison inmate, played by Todd Duncan, and is accompanied by free flowing arpeggios on a guitar played by another inmate. The lyrics mourn that it has been a long time since the inmate has seen their love, and he entreats his darling to wait for him to come home.

Oh, my love, my darling 
I've hungered for your touch 
A long, lonely time 
Time goes by so slowly 
And time can do so much 
Are you still mine? 
I need your love 
I need your love 
God speed your love to me
Lonely rivers flow 
To the sea, to the sea 
To the open arms of the sea 
Lonely rivers sigh 
"Wait for me, wait for me" 
I'll be coming home, wait for me

When most people think of Unchained Melody, they tend to think of the Righteous Brothers version, originally released in 1965. This version set the standard for many covers since then, changing the time signature from 4/4 to 12/8.  Bobby Hatfield won the coin toss to sing the solo vocals, and Bill Medley produced the song (originally uncredited) and played the electric piano in the backing. The tune starts off fairly simply, with a soft drum kit hitting a closed hi-hat continuously, gentle arpeggios, a muted quick chord on the off beats, and Bobby's voice gently singing. The emotion starts to build after a few lines when the strings come in to wander around and vocals start to soothe in the background. Bobby's voice soars when he asks his lover, "Are you still mine?" then falls downwards in frills, husky with need. On the second repeat of the song's lyrics, the drum kit steps forward from the background and the rest of the background becomes more bold also. Bobby's voice breaks from the original melody to soar even higher, "I need your love!" before becoming more subdued and settling into the melody again. The fullness of the backing continues after the lyrics end and the song ends on a triumphant note.

The Righteous Brothers version proved a huge hit with radio DJs, and also filled jukeboxes right across America. In 1990, the movie Ghost used this version, resurrecting it and cementing its popularity in a whole new generation.

Unchained Melody has been covered by many artists, including many big names. The following is by no means an exhaustive list of them:

Les Baxter orchaestra
Al Hibbler
Jimmy Young
Harry Balefonte
Liberace
Roy Hamilton
June Valli
Bing Crosby
Vito and the Salutations (in an uptempo doo-wop version, harsh by comparison to other versions and used in the movie Goodfellas, 1990)
Elvis Presley
Perry Como
The Platters
Roy Orbison
U2
Neil Diamond
LeAnn Rimes
Barry Manilow
Robson & Jerome (who sang it in a TV episode of Solider Soldier and thereafter were approached by Simon Cowell to record it properly)
Gareth Gates (on Pop Idol, making it all the way to the finals and reprising the song as his personal choice song)