24 fps, blue ray and my telly.
 

Snort! Bah! Humbug!

Sorry! I should have contented myself with: "You are probably
mistaken!"

As far as pop music was concerned, most record companies were/are only
interested in a quick buck. If the band tunes up off 'concert pitch',
as long as they're in tune with each other, what's it to the company?
(Though one would hope a good manager might sort them out.)

The same or very similar recording systems were used for both
classical and popular, so I think the difference you claim can simply
be put down to the musician's involved. Lonnie Donegan was also Kenny
Ball's banjo player. Jazz musicians, like classical, tend to be a lot
more professional about such things.

You were also relying on the speed of your turntable being accurate,
many, perhaps even most, weren't too hot. My old Dual has a strobe to
get the speed right, though of course that relies on the mains being
sufficiently accurate, not sure what the figures for that would be.

In fact, 'concert pitch', where the a' note is standardised at 440Hz,
is a comparatively new standard dating only from May 1939.

Despite its existence, it still seems to be widely disregarded in
informal music like folk sessions and also some popular music,
particularly where there isn't an absolutely pitched instrument like a
keyboard to tune to.

I have an electronic tuner, though from habit I still tend to use a
tuning fork to tune the top E-string of my guitars, and then
cross-tune using the harmonics, but whichever way, I often find that
when I try to play along with something I've recorded off the radio,
it's not in concert pitch.

But at least we're all a lot more accurate than we used to be! In
fact it's the broadcasting and recording era that has largely
reinforced the need for a standard.

Music for the highland pipes is traditionally written in A, but by a
statistical process known informally as "drunkard's walk" (slight
error on slight error accumulating over a long period of time) one can
usually now accompany pipe tunes on a B Flat whistle by slight
adjustment of the mouthpiece.

But the wider variations in pitch before 'Concert' are certainly
startling to any musician, almost staggering (this table requires a
fixed pitch font, if your newsreader doesn't use one, cut 'n' paste it
into Notepad or equivalent). Note that the lowest value is 373.7Hz in
1648, and the highest 567Hz in 1619, differences of 40 and 60% from
their average!
Date a' (Hz)
Halberstadt Organ 1361 505.8
Church Pitch, Heidelberg 1511 377
Ditto, North Germany 1619 567.3
Ditto, Paris 1648 373.7
Schnitger's Organ, Hamburg 1688 489
Paris Opera 1699 404
Silbermann's Organ, Strassburg 1713 393
Handel's Tuning-Fork 1751 422.5
Bernhardt Schmidt's Organ, Cambridge 1759 395.2
Paris Opera 1810 423
London Philharmonic Orchestra 1826 433
Paris Opera 1858 428
French Standard Pitch (diapason normal) 1859 435
Covent Garden Opera 1879 450
Philharmonic Society 1896 439
Piano Manufacturers 1899 439
Military bands (Army Council) 1927 439

Source ...
Alexander Wood, The Physics Of Music, 7th ed'n
ISBN 0 412 13250 8
ISBN 0 412 21140 8
.... quoting Alexander Ellis, History Of Musical Pitch.

On Sun, 7 Sep 2008 11:27:20 +0100, Ian Jackson
wrote:

I would have thought that the record companies would have gone to great
lengths to ensure that they got the pitch correct. Presumably the error
was caused by something in the chain being processed at the wrong speed.
Was I mistaken, or was there some subtle reason for these differences?

24 fps, blue ray and my telly.
 

In article , Java Jive
writes

You were also relying on the speed of your turntable being accurate,
many, perhaps even most, weren't too hot. My old Dual has a strobe to
get the speed right, though of course that relies on the mains being
sufficiently accurate, not sure what the figures for that would be.

Legally limited to +/-1%, driven by the load on the National Grid at any
time, about 4x less than speeding up 24Hz to 25Hz.

You can see the current balance of demand and supply on the grid
frequency in almost real time at:
http://www.dynamicdemand.co.uk/grid.htm

If you watch at times of major events where a significant portion of the
nation switches on kettles or flushes toilets at the same time it gets
pretty close to the minimum limit, having usually preceded that with a
minute or two close to the maximum limit as the power planners ramp up
generation in preparation for the surge.

--
Kennedy
Yes, Socrates himself is particularly missed;
A lovely little thinker, but a bugger when he's ****ed.
Python Philosophers (replace 'nospam' with 'kennedym' when replying)

24 fps, blue ray and my telly.
 

"Kennedy McEwen" wrote in message
...
You can see the current balance of demand and supply on the grid frequency
in almost real time at:
http://www.dynamicdemand.co.uk/grid.htm

Why does the supply frequency vary with load?

Bill

24 fps, blue ray and my telly.
 

On 07/09/2008 22:23, Bill Wright wrote:

Why does the supply frequency vary with load?

What happens to your van if you approach a hill and don't push the loud
pedal hard enough?

24 fps, blue ray and my telly.
 

On Sun, 07 Sep 2008 22:30:45 +0100, Andy Burns
wrote:

On 07/09/2008 22:23, Bill Wright wrote:

Why does the supply frequency vary with load?

What happens to your van if you approach a hill and don't push the loud
pedal hard enough?

An even closer analogy is belting along on the level in the van
with the loud pedal as far down as possible and then meeting a
hill. If the hill is up, the van will go slower - lower
frequency of rotation of the wheels. If the hill is down, the
van will go faster - higher frequency of rotation of the wheels.

24 fps, blue ray and my telly.
 

"Peter Duncanson" wrote in message
...
On Sun, 07 Sep 2008 22:30:45 +0100, Andy Burns
wrote:

On 07/09/2008 22:23, Bill Wright wrote:

Why does the supply frequency vary with load?

What happens to your van if you approach a hill and don't push the loud
pedal hard enough?

An even closer analogy is belting along on the level in the van
with the loud pedal as far down as possible and then meeting a
hill. If the hill is up, the van will go slower - lower
frequency of rotation of the wheels. If the hill is down, the
van will go faster - higher frequency of rotation of the wheels.

All this is obvious. But are you saying that the speed of all the turbines
is governed by simple mechanical load? I assumed things would be more
sophisticated. How are the turbines synced?

How does the frequency variation tie in with the voltage fluctuations we
get?

Could it be that the speed is deliberately allowed to reduce to balance the
load?

How does the amount of energy delivered for a given voltage vary with supply
frequency?

I do know that when I was at college (in the sticks) our gramphones used to
have to be set at 78 to play 45s during January. As you will gather none of
us had perfect pitch.

Bill

24 fps, blue ray and my telly.
 

Bill Wright wrote:

Why does the supply frequency vary with load?


I assume the generator regulation is such that they can't drop the
voltage without dropping the spin speed. It surprised me too. I
assumed they'd just weaken the fields in the rotors, and keep the spin
speed the same.

Andy

24 fps, blue ray and my telly.
 

On 07/09/2008 23:35, Bill Wright wrote:

All this is obvious. But are you saying that the speed of all the turbines
is governed by simple mechanical load?

Yes.

I assumed things would be more
sophisticated. How are the turbines synced?

The bit that requires care is getting them synced before joining them to
the grid, after that point they become locked to the grid frequency, all
generators are "dragged" to their common frequency.

How does the frequency variation tie in with the voltage fluctuations we
get?

Could it be that the speed is deliberately allowed to reduce to balance the
load?

Over the allowed frequency range I don't suppose it would have much
effect. Do they still "make good" the overall cycle count for the day
overnight? (i.e. make it up to 4,320,000)

How does the amount of energy delivered for a given voltage vary with supply
frequency?

Higher frequency waves of same amplitude have higher energy don't they?

24 fps, blue ray and my telly.
 

"Andy Champ" wrote in message
...
Bill Wright wrote:

Why does the supply frequency vary with load?


I assume the generator regulation is such that they can't drop the voltage
without dropping the spin speed. It surprised me too. I assumed they'd
just weaken the fields in the rotors, and keep the spin speed the same.

It does seem odd. After all, synchronisation would be easier with a constant
speed I would have thought. Never mind, so-one will be along in a minute to
answer all our questions.

Bill

24 fps, blue ray and my telly.
 

On Sun, 7 Sep 2008 23:58:26 +0100, "Bill Wright"
wrote:


"Andy Champ" wrote in message
...
Bill Wright wrote:

Why does the supply frequency vary with load?


I assume the generator regulation is such that they can't drop the voltage
without dropping the spin speed. It surprised me too. I assumed they'd
just weaken the fields in the rotors, and keep the spin speed the same.

It does seem odd. After all, synchronisation would be easier with a constant
speed I would have thought. Never mind, so-one will be along in a minute to
answer all our questions.

Once an alternator has been brought into synch and connected to
the grid it will remain in synch. Basically, if an alternator
gets out of synch there will be a phase difference between its
voltage and the voltage on the grid. This will cause current to
flow *into* the alternator treating it as a motor, speeding it
up or slowing it down until it is back in phase.

Or something like that.