Burt Bacharach: 'Knowing When to Leave,' 1968

The song from 'Promises, Promises' was covered by many artists, including Sue Raney

Composer-arranger Burt Bacharach’s only successful Broadway score was for the 1968 musical Promises, Promises, with lyrics by Hal David and a book by Neil Simon. The title song became a huge hit, but the sleeper was Knowing When to Leave, sung in the original production by Jill O’Hara, who played the Fran Kubelik character. [Photo above of Burt Bacharach in 1970, courtesy of ITV/Rex Features]