THIS IS THE BBC! DO NOT LISTEN TO THE OTHERS, THEY ARE THE FALSE PROPHETS!

How it was made: https://www.bbc.co.uk/news/videos/c3ge48d0v4go

It references the Greenwich pips played on BBC radio stations so people know they're on time: https://en.wikipedia.org/wiki/Greenwich_Time_Signal

If you want to play along:

    countdown bass chord
       46      Bb   Bbm
       42      Bb   Eb
       38      Bb   Bbm
       34      Bb   Eb
       30      Bb   Bbm
       26      F    Fm
       22      Gb   Gb
       18      Eb   Eb
       14      Gb   Gb
       10      Bb'  Eb
        6      Bb'  Bb