"Wonderful Tonight" written by Eric Clapton, is from his 1977 album Slowhand. The female vocal harmonies on the song are provided by Marcella Detroit (then Marcy Levy) and Yvonne Elliman.
https://en.wikipedia.org/wiki/Wonderful_Tonight
https://en.wikipedia.org/wiki/Slowhand_(album)
https://en.wikipedia.org/wiki/Eric_Clapton
https://en.wikipedia.org/wiki/Wonderful_Tonight
https://en.wikipedia.org/wiki/Slowhand_(album)
https://en.wikipedia.org/wiki/Eric_Clapton