A little history
"How Deep Is Your Love" was writen and performed by "The
Bee Gees".
The Bee Gees wrote this originally for American singer Yvonne Elliman. Elliman did sing "If I Can't Have You," which was written by The Bee
Gees and included on the soundtrack.
This song won the 1977 Grammy Award for Best Pop Performance By A Group and was a massive hit in the US.
Info courtesy of: http://www.songfacts.com
How Deep Is Your Love.
Robert Stigwood, who produced the movie Saturday Night
Fever, insisted the Bee Gees perform it themselves for the soundtrack.
That song was also a #1 hit in the US.
It stayed in the Top-10 for 17 weeks, which was a record at the time.