It's possibly because there are umpteen versions available, from performances by various orchestras (BBC Concert Orchestra to Philomusica of Edinburgh), through versions with added lyrics (one by Bernard Loughrey, others including a male voice choir and one by Binge himself and the Wimbledon Girl Singers), to people who captured it from broadcasts; as well as Wikipedia articles that are easily discoverable.

The UK Theme also has several broadcast versions, alone, of differing lengths.

* https://en.wikipedia.org/wiki/Sailing_By

* https://www.youtube.com/watch?v=Pr-T3vXbj8c

* https://www.youtube.com/watch?v=p6vDtPOhDqA

* https://www.youtube.com/watch?v=vSvf_wMfzLE

* https://www.youtube.com/watch?v=pFfftvIVVyo

* https://www.youtube.com/watch?v=CP_4w6GOQS0

* https://www.youtube.com/watch?v=QlPSuqXlS4I

* https://en.wikipedia.org/wiki/Radio_4_UK_Theme