<Tr> <Th> Producer (s) </Th> <Td> <Ul> <Li> Björn Ulvaeus </Li> <Li> Benny Andersson </Li> <Li> Tim Rice </Li> </Ul> </Td> </Tr> <Ul> <Li> Björn Ulvaeus </Li> <Li> Benny Andersson </Li> <Li> Tim Rice </Li> </Ul> <P> "I Know Him So Well" is a duet from the concept album and subsequent musical Chess by Tim Rice, Benny Andersson and Björn Ulvaeus . It was originally sung by Elaine Paige (as Florence) and Barbara Dickson (as Svetlana). In this duet, two women--Svetlana, the Russian chess champion's estranged wife, and Florence, his mistress--express their bittersweet feelings for him and at seeing their relationships fall apart . </P> <P> The duet was first released worldwide on the Chess double LP, often referred to as a concept album or album musical, in the autumn of 1984 . Later it was released as a single by Paige and Dickson, the duet reaching number one in the UK Singles Chart for four weeks in 1985 . They laid down their vocals separately and never met during the recording of the song, only for the video and subsequent performances on Top of the Pops and the European tours . This recording remains in the Guinness Book of Records as the biggest selling UK Chart single ever by a female duo . Paige also appeared in the original London West End stage production of Chess . </P>

Who sang the song i know him so well