'Trysting Fields and Sheep 'n' Tides comes from the soundtrack of the 1988 film 'Drowning by Numbers' directed by Peter Greenaway.

The music is performed by the Michael Nyman Band and is available on the MN Records release 'Nyman/Greenaway Revisited': http://bit.ly/2fd4bVg

Nyman's composition is entirely based on themes from the slow movement of Mozart's Sinfonia Concertante in E flat, bars 58 to 61, which is also heard in the film.