It's true what they say, then: a good songwriter never lets a melody go to waste.

Someone with altogether too much time on their hands has unearthed footage of Paul McCartney playing part of the melody of Kanye West's 'All Day' - which he recently co-wrote with the rapper - on Parkinson back in 1999.

The song was actually originally an unreleased and untitled Beatles song dating from the late 1960s, but fans have come to know it as 'When the Wind is Blowing'.

Macca played a snippet of the track on Parky's show, whistling the melody.

Watch it below - and then check out Yeezy's 'All Day' below that for comparison: