The theme, which is written in the key of E-flat major, is largely based upon percussion instrument, strings and the piano. It is widely known for its dramatic use of sound, particularly the drums that begin at the end of an episode – which adds a sense of importance, suspense and drama to the cliff-hanger. This in itself, has been parodied and used by television shows since, such as in a "Friends" spoof that featured on "SMTV Live". The drum fill was written and played by Graham Broad.