“How Deep Is Your Love” is a 1977 single by the Bee Gees. Originally intended for singer Yvonne Elliman, their request was declined and the Bee Gees decided to sing it themselves.

The song is part of the soundtrack to the film Saturday Night Fever. It topped the US charts on Christmas week 1977, and remained in the US Billboard top 10 for a record 17 weeks. The song also went #1 in Canada, France, and Brazil.

This song has been covered numerous times, including by Tina Turner, Lea Michele, Backstreet Boys and N'Sync.

https://www.youtube.com/watch?v=XpqqjU7u5Yc