"When I Need You" is a popular song written by Albert Hammond and Carole Bayer Sager. Its first appearance was as the title track of Hammond's 1976 album When I Need You. Leo Sayer's version, produced by Richard Perry, was a massive hit worldwide, reaching number 1 on the UK Singles Chart for three weeks in February 1977 after three of his earlier singles had stalled at number 2. It also reached number 1 on both the Billboard Hot 100 for a single week in May 1977; and the Hot Adult Contemporary Tracks.Billboard ranked it as the No. 24 song of 1977. Sayer performed it on the second show of the third season of The Muppet Show.

The melody of the "hook" line, or chorus of "When I Need You" is identical to the part of the Leonard Cohen song "Famous Blue Raincoat", where the lyrics are as follows: "Jane came by with a lock of your hair, she said that you gave it to her that night, that you planned to go clear." The melody of these lyrics matches the lyrics of "When I Need You" as follows: "(When I) need you, I just close my eyes and I'm with you, and all that I so want to give you, is only a heart beat away."

In a 2006 interview with the Globe & Mail Cohen said:

I once had that nicking happen with Leo Sayer. Do you remember that song 'When I Need You'?" Cohen sings the chorus of Sayer's number one hit from 1977, then segues into 'And Jane came by with a lock of your hair', a lyric from 'Famous Blue Raincoat'. 'Somebody sued them on my behalf … and they did settle', even though, he laughs, 'they hired a musicologist, who said, that particular motif was in the public domain and, in fact, could be traced back as far as Schubert.

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