Van der Valk (1972)

This is the 1972 Thames Television detective series starring Barry Foster, not the 2020 revival. Its theme, Eye Level, was a library track by the Dutch composer Jan Stoeckart under the name Jack Trombey, recorded by the Simon Park Orchestra. Then it did something no detective theme should: it went to number one. Reissued in 1973, it spent four weeks at the top of the UK singles chart. The appeal is an easygoing, wide-open melody that feels more like a canal-side stroll than a murder inquiry, and it may be better remembered now than the show itself.