How Deep Is Your Love.

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.
Robert Stigwood, who produced the movie Saturday Night Fever, insisted the Bee Gees perform it themselves for the soundtrack.

 Elliman did sing "If I Can't Have You," which was written by The Bee Gees and included on the soundtrack.
That song was also a #1 hit in the US.

This song won the 1977 Grammy Award for Best Pop Performance By A Group and was a massive hit in the US.
It stayed in the Top-10 for 17 weeks, which was a record at the time.

Info courtesy of: http://www.songfacts.com