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The BBC World Service Radio pips (or beeps) are an iconic aspect of the radio program broadcast around the planet by shortwave radio as well as the internet now.

The 2 minute podcast A brand new sound for the BBC World Service has the annotation:

There's a brand new sound for the BBC World Service with a new signature tune and complementary music for key programmes across our network.

The music was composed by Mcasso, one of the UK's leading music and sound companies. We went along to film their recording with the string section of the BBC Concert Orchestra at Angel Recording Studios in Islington, London.

(Photo: BBC Concert Orchestra. Credit: BBC)

Release date: 10 September 2018

The pips are described in Wikipedia:

There are six pips (short beeps) in total, which occur on each of the 5 seconds leading up to the hour and on the hour itself. Each pip is a 1 kHz tone (about halfway between musical B5 and C6) the first five of which last a tenth of a second each, while the final pip lasts half a second. The actual moment when the hour changes – the "on-time marker" – is at the very beginning of the last pip.

I believe that the A above "middle C" on a piano is the one commonly matched to 440 Hz, so I am guessing that C6 in the quote is the one two octaves above "middle C".

Question: Is there any way to know exactly how far the orchestra would have had to be "de-tuned" to perfectly match the 1 kHz tone? Which would require less adjustment, writing the piece in the key of B or in C?

"bonus points" if someone knows if they in fact did tune accordingly, or if it was so close that they didn't.

below: Screenshot from the linked BBC page, though it's out of focus and difficult to read. Also, the title is "Business Daily" and so this may not even be the correct score.

BBC World Service musical score

below: Greenwich Time Signal 1970.jpg from here.

BBC's Greenwich Time Signal Machine from 1970's

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    B5 is 987.7666024017 Hz, C6 is 1046.5022610267 Hz, so B5 is closer, but 1000 Hz would sound like a B that's almost an eighth tone sharp, which is definitely noticeable. – Your Uncle Bob Sep 12 '18 at 7:39
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    @YourUncleBob that looks a lot like the answer to my question; I don't think that there's anything missing. Would you consider posting it as one? – uhoh Sep 12 '18 at 7:43
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    Years ago as a kid playing guitar with no good tuners available, I used the BBC pips as a B reference. – Tim Sep 12 '18 at 9:25
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    I read a story some time ago, maybe as many as 10 years ago, that a music professor wrote to the BBC to say that the pitch had dropped and it was now close to B flat. He requested that this be the new standard. However, they checked the equipment, found a fault, and restored the 1kHz. Unfortunately, I have failed to find a reference fie this story. – badjohn Sep 12 '18 at 14:37
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    At one point, I thought it might have been an idea to have the beeps go - b b BBC... at concert pitch. – Tim Sep 12 '18 at 16:53
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The frequencies of B5 and C6, when using standard 440Hz tuning, are:

B5:  987.767 Hz  
C6: 1046.502 Hz

As you can see, 1000Hz is closer to B5. Using the standard way of describing pitch on a logarithmic scale, where a semitone is divided into 100 cents, we find that either:

1000Hz = B5 + 21.31 cents
1000Hz = C6 - 78.69 cents

A tuning difference of 21 cents would be clearly audible, even to the untrained ear.

In terms of tuning the orchestra to match the 1000Hz pips, they'd have to be tuned to:

A4 = 445.449 Hz

for B5 to be 1000Hz. This isn't really a radical detuning for classical instruments. At various times throughout history, pitches as high as 452Hz were used as standard; even today, some orchestras tune as high as 443Hz (see: History of pitch standards in Western music).

When tuning down to get C6 to be 1000Hz, they'd have to go as low as:

A4 = 420.448 Hz

As for the fragment heard in the podcast, the pips you hear in it are actually tuned to 1001.6Hz, with the orchestra roughly in tune with it (but slightly flat to my ears), so it's not clear what's going on there; maybe we're not hearing the final product, or the video was sped up slightly during the editing or transfer to the video format used on the website.

  • I think if you asked the string section to tune up to 445 you might get a revolt. That would be very stressful on the instruments. Better to tune down to a nice 1800-style level, setting C to 500 Hz and A proportionately low – Carl Witthoft Sep 12 '18 at 15:19
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    @CarlWitthoft Apparently the Berliner Philharmoniker used to tune to 445 under von Karajan, and have now dropped to 443. I'm guessing he had the authority to quell any revolt :-) – Your Uncle Bob Sep 12 '18 at 15:27
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    @CarlWitthoft I've added a flat tuning for those worried about breaking their instruments or being decapitated by snapped strings. – Your Uncle Bob Sep 12 '18 at 15:38
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    You added a good point there at the end - with the exception of a live performance, it's trivial to shift the pitch of the entire orchestra in post-processing. – Carl Witthoft Sep 12 '18 at 19:27
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    Actually when you embed the tone as third in a gis minor triad you gain 14ct for free so the difference in this particular chord reduces to 7ct. Regarding strings: Some string concerts are written in Es in order to damp the main strings. In that case solists are advised to raise the tuning of their instrument by a semitone so that it regains the brilliance of the resonating strings. – Tobias Schlemmer Sep 13 '18 at 7:20

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