The fanfare was preceded by a quite remarkable arrangement of The British Grenadiers – a tune that dates back in written form to 1740. Who arranged the Associated-Rediffusion version is not known, but it is interesting to note that the tune was used extensively by Franz Waxman in his 1955 score for the film The Virgin Queen, starring Bette Davis – but without listening to it we can’t tell if this is a red herring or not.

Following Mitchell’s announcement is an excerpt from a familiar and appropriate work: Elgar’s concert overture, Cockaigne (In London Town), op. 40, although it crashes in rather abruptly.

This completes the best-known of Associated-Rediffusion’s early daily start-up routines – used from September 1955 to September 1956.

What is not so well known – in fact I have never seen it documented – is that there was a second routine used during the same period. It includes the same excerpt from Cockaigne and the same fanfare by Williams, but the voice-over is female rather than male (though using the same script), and there is a completely different station theme at the front.

Readers of my previous article will recall that I was lucky enough to be sent a tape of Rediffusion’s Schools Interludes by the person who used to play the original discs on-air. He included a number of other goodies on the tape: two of them are marked "A-RTV Afternoon Intro" and "A-RTV Evening Intro", and these, transcribed from 78 rpm discs by the sound of it, are the sequences we are discussing here. The "Evening Intro" is the well-known one featuring Leslie Mitchell, which would have been broadcast at 18:55; the "Afternoon Intro" is the other, and would have gone out at 16:55, the station going off the air between 18:00 and 18:50.

This tuning signal was probably the one shown while the station theme was playing

I have had this tape for something like 20 years, I imagine and, like the Arne piece in the Schools Interludes, I wondered what the music was. This despite the fact that I was four when A-RTV started and we didn’t even have television in the house until 1960 (I worked this out recently from the fact that I can remember Pathfinders In Space!) and even if we had, I was brought up in the land of ATV and ABC, in the Midlands, a good hundred miles from any of A-R’s output. By the time we moved back to London, A-R was on the point of metamorphosing into "Rediffusion, London" with quite a different air about it and, no doubt, Johnny Dankworth’s Widespread World of Rediffusion as its station theme.

One day I was visiting some friends at the Findhorn Foundation near Inverness. Every Friday night they show a movie in the Hall, and walking in there on one such evening near the end of the film, I heard a familiar piece of music: the piece from the Afternoon Intro – or something like it, anyway. I asked what the movie was, and it turned out to be David Lean’s 1945 film of Noel Coward’s comedy, Blithe Spirit, about an author (Rex Harrison) haunted by the spirit of his dead first wife, Elvira (Kay Hammond) and how it impacts his life with his second.

Some years later, I encountered the movie again on TV (again missing the beginning) and there again was this piece of music – with its strong echoes of the A-RTV recording. It was obviously the same basic tune, but a rather different arrangement.

I never really did anything with this information until quite recently. Having started to discover the wealth of information and knowledge in the Transdiffusion archives, I decided to transfer the old Rediffusion pieces to digital in case they might end up on one of the microsites.

I happened to mention the afternoon intro to my friend Peter Carbines – and it turned out that he had Blithe Spirit on tape. "Have a listen to the last few scenes," I told him, sending him an MP3 of the Afternoon Intro, "and see if you think it’s similar".

He wrote back, "…although there are some recognisable figures in the music, it’s not quite what you are after. I’ve recorded the opening titles, which you will find are more like the piece you’ve sent." Lo and behold, the MP3 file he sent me of Blithe Spirit’s opening titles – which I had always missed before – was very, very close to the first three minutes, ten seconds of music in the Afternoon Intro.

But not quite the same. The end of the movie’s opening titles dissolves into the incidental music at the start of the film, while the Intro piece has a very determined ending. As in the world of library music, there are no fades in the TV station themes business. Pieces have to end. In addition, there are some extra touches in the Intro version of the music, notably a hint of the 14-note figure that British children know as the tune to the nursery rhyme "Oranges and Lemons" which features the bells of various London churches – appropriate for a company aiming to give London "The Best of All Television".

• Listen to the "Afternoon Intro" ("Blithe Spirit")
  - Audio Only (1.4 MB MP3) ("Blithe Spirit", Female V/O & Williams "Fanfare No.1", Excerpt from Elgar's "Cockaigne")
• Hear the opening music to the 1945 David Lean movie, "Blithe Spirit", score by Richard Addinsell
  (edited to remove dialog - 750KB MP3)

Looking at the music credits for Blithe Spirit, I immediately noticed a familiar composer’s name: that of Richard Addinsell. Addinsell (1904-1977) has had the perhaps unfortunate fate of not only being eclipsed by a piece of his music, but by the name of a piece of his music. Say "Richard Addinsell" to people and they will ask, "Who?" But say Warsaw Concerto to them and they can probably hum it – at least they can if they are over about 50, listen to Classic FM, or are Spike Milligan fans.

Warsaw Concerto was the Rachmaninov-like musical highlight of the film Dangerous Moonlight (1941) in which Polish piano virtuoso Stefan Radetzky escapes from Warsaw only to return to the war to fight. Addinsell wrote this and a great many other film scores from the 30s right up to the 60s, and Associated-Rediffusion’s earliest Afternoon Intro is not the only place he turns up in British television’s musical history.

There are still unanswered questions concerning A-RTV’s earliest daily startup routines. Who is the female voiceover, for example? And who arranged British Grenadiers? When was the "Afternoon Intro" actually broadcast? (It may have been transmitted just before 5pm; possibly more likely is that it preceded the short-lived A-R service aimed at housewives that began at 1pm.) But at least one mystery is solved: Richard Addinsell provided Associated-Rediffusion’s Blithe Spirit.