Most MP3's that you'll find through file sharing networks employ a Joint Stereo audio track. Joint Stereo is an attempt at reducing the size of a file while still retaining "stereo" signals. In a joint stereo file, the compressor takes advantage of the fact that both stereo channels contain mostly the same information most of the time. So, when the two channels are similar, instead of compressing both a Left and Right channel, it adds the two together and produces a middle (L+R) and a side (L-R) channel. This allows a reduction in the final size of the file by using less bits for the side channel. During playback, the decoder will reconstruct the left and right channels from the middle and side data.

Sounds great, right? Well, not really, because when the middle and side channels are created, a lot of information from the original Left and Right channels is lost. This lost data generally ends up being subtle harmonics and tonal depth, and without it, you end up with a flat sound.

But not just yet; there's so... much... 80s music! So much downloading to do!

UPDATE: Aw hell... there's the e-mail invoice for today's music purchasing frenzy.

$10.89.

For what would normally have cost me around $50 in whole CDs, most of which I didn't actually want, plus gas and time.

UPDATE: Chris has a few more details:

The 'joint stereo' is usually applied to low frequency effects, because the ear can't tell whether it's coming from the left, or right, as much as middle or higher frequencies. This is why you can put your subwoofer off to one side and still have a good stereo environment.

However, the key is the 'as much' part. It's not a straight cutoff, but a lowering of the spatial perception as the frequencies get lower. I'm sure different people have different cutoffs, too, so the whole 'joint stereo' thing is an approximation; much better to just KEEP them separate, if you have the bandwidth to spare.

UPDATE: Oh yes: What happens if you pay for a song, but then your Net connection gets cut off before you can finish downloading it? Good question. Apparently the credit-card transaction occurs at the time you click to begin the download; but Apple records whether the download completed successfully, so you can then go back with the Advanced->Check for Purchased Music option, and if there's anything pending, you can re-download it. However, there doesn't seem to be a facility to re-download tracks that you are "entitled to"; you can, if you choose, pay for a song a second time. It doesn't protect you against the loss of all the copies you might have of the file; that's your responsibility.

UPDATE: Here's some info from Apple on the authorization/deauthorization process. One interesting bit:

Note: Initializing the drive will not deauthorize the computer. If you will be initializing the drive, deauthorize the computer first, then initialize the drive.

So the authorization status survives a drive reformat? I guess that means the status is governed by the central server primarily; I guess it also means you can't fool the system if you take a computer that's been deauthorized, then restore its disk image from a backup that still thinks it's authorized (and then never connect to the Music Store again). I wonder how this is done...

Another UPDATE: Several people have called my attention to the fact that the Music Store has a "Request" mechanism-- three links down on the main screen, you can fill out a form to request that they add your suggested artist, album, song, genre, or whatever. No real indication of how binding that would be-- but it tells me that the selection is bound to start blossoming in the near future. The current omissions are presumably a result the taste of whoever made the initial selections for populating the database, rather than any contractual obligations.

Cool.

UPDATE: Here's the nitty-gritty of the DRM terms:

The iTunes Music Store is fast and convenient for you, and fair to the artists and record companies. In a nutshell, you can play your music on up to three computers, enjoy unlimited synching with your iPods, burn unlimited CDs of individual songs, and burn unchanged playlists up to 10 times each.

Okay-- that answers a number of questions, and raises quite a few more...

UPDATE: As of 4:00 PM PST, the kinks in the service seem to be worked out; I can now sign in, search, browse, and move around the system with very little delay. Guess they got some more servers online.

Also, Chris points out to me that the purpose of moving the iPod's playback/navigation buttons to a row above the scroll wheel, instead of their previous ring around the wheel, is to allow them to go the the touch-sensitive track-pad sensor buttons for all of them, not just the wheel. (Early iPod owners complained a lot about taking their iPods to the beach and getting sand in the scroll-wheel, hence the move to the track-pad wheel.) If they'd stayed with the old button layout, but made the ring buttons touch-sensitive, there would be no tactile separation between them and the scroll-wheel; moving them to the row above lets the user navigate by feel as well as keeping the sand out.

"The Iraqi air force understood that it needed to stay on the ground for its own safety," said Gen. Peter Cosgrove, chief of the Australian Defense Forces, who spoke to troops at the airfield on Thursday.

The Al Asad airfield, which housed the largest known contingent of Saddam's jet fighters, represents one of the big catches of the war. Three fighter squadrons -- the bulk of the Iraqi air force -- were stationed there, 112 miles northwest of Baghdad.

The Australians say they are still taking inventory but have so far found 57 fighter aircraft, mostly Soviet-era MiGs but also three advanced MiG 25 Foxbats, the fastest combat aircraft today.

(Sorry.)

(No I'm not.)

From 1997 to 2001, Tatara appeared frequently, as often as 16 times a month, along with the critic who actually appeared on TV, Paul Clinton. In 2002, his workload suddenly dropped to, at most, five reviews a month. There were times in the past that CNN.com editors had told Tatara that the higher-ups weren't loving his work, and more and more the site was relying on Entertainment Weekly, its sister AOL Time Warner publication.

"There were always periods, after nine months or so, when someone would raise a stink about the tone of writing being too conversational, too harsh, too, too, too," says Tatara, who is not speaking in exclamation points at this moment. He's just warming up.

"Especially with the conversational tone. They wanted me to be faceless!"

"It could be that [CNN's] blood pressure was higher, because the site wasn't making money! I had a real readership, but they couldn't care less! They weren't allowing people any real personality! At this point, [CNN] is like the Kmart of news services, and instead of a news flash, they should have a Blue Light Special!"

Geez... that was about the easiest piece of online research I've ever had to do. URLs practically hurled themselves at me.

-An inquiry about proposal one, re-electing the board of directors, asked if there really was any choice at all in the re-election of the board, since Apple's shareholder notice notes "The six nominees for director receiving the highest number of affirmative votes of the shares entitled to be voted for them shall be elected as directors." There were a total of six nominees. Heinen said that people did have the option of not voting. Jobs then commented that he received 83% of the votes to be re-elected, the highest second to Al Gore who received over 90%. Gore added, "Does it matter who has the most votes?" which sent the crowd into laughter.

-A person expressed concern over dealership contract renewal . Cook responded saying that dealerships representing less than 0.2% of Apple's revenue didn't re-sign. He also said that some dealerships re-signed after the deadline, and that the number of signed-on dealerships will only go up with time. Jobs added, humorously, that 100% of the Apple Retail stores decided to renew their contracts.

-A woman asked about increasing market share, and what steps to take if one identified possible large corporate sales opportunities for Apple. Fielding the second question first, Jobs made Cook provide his e-mail address to shareholders, so that he could handle their suggestions about enterprise sales opportunities -- tcook@apple.com. Fred Anderson then answered the first question explaining that the Switch campaign has been working, and that among the consumer segment Apple has doubled its market share, based on information from IDC.

-The acquisition of Virtual PC by Microsoft was raised by one shareholder. Jobs said that Apple's relationship with Microsoft is good and that Microsoft likes Safari. He also noted that VPC has been moved to the Mac Business Unit at Microsoft and that Microsoft acquired the software not so that it could get VPC itself, but its underlying technology. Jobs said Apple has talked with Microsoft, and Microsoft promises to continue the software. Jobs also suggested that the price might drop since royalties on Windows no longer have to be paid.

Wait a minute. Doubled its market share? You've gotta be kidding me.

What, we're up to 2% now?

Nevertheless, I agree with what he said. I don't think Bush was legitimately elected President. But I was very offended as a reporter when Michael came directly back to the pressroom where I was, along with 300 or 400 other reporters, and lectured us, "Now do your job. Don't report it was a divided house. Only five loud people were booing."

The paper describes "Piles" as an adjunct to the file/folder metaphor, in the paper (co-authored with Richard Mander and Yin Yin Wong). A clue is in the title, which describes piles as a metaphor for "supporting casual organization of information".

Piles were seen as complementary to the folder filing system, which was used more for archiving than grouping recently used, but related documents. "The folder as the sole container type presents an impoverished set of possibilities," the authors noted.

"There are different aspects to Piles," Solomon told us today. "They are a visual representation, but also helping them organize things, as a way to make suggestions. There are fuzzy edges - the computer is presenting you with 'what if?' questions on a pile of stuff.

This would be helped indexing of the contents of documents in real time, much as BeOS' BFS file system indexed metadata attributes in real time using a dedicated system thread. BFS designer Dominic Giampaulo joined Apple last year, and the rumor circuit has consistently suggested that better threading is a priority for the Panther update to MacOS X. Which suggests that Apple has both the will and know-how to provide a system capable of supporting very rich Piles.

At least North Korea publicly stated that they were backing out of the ABM treaty; we, instead, have simply reversed our policy, and are re-arming for a new nuclear-armed world. Our people at STRATCOM are seeking out and designating new nuclear targets in Iraq and elsewhere as we speak. And the Bush administration made a statement early in this war that said that if the Iraqis should use chemical or biologcal weapons against the American troops, then we would use "any force necessary" in response-- which, of course, is diplomatese for "nuclear weapons". And we should also realize that the US is more aggressively developing nuclear weapons today than ever before; now we've got these so-called "bunker busters", which, uh, can take out certain underground installations. These "bunker busters" are nuclear weapons which further demonstrate that the US is committed to a double standard regarding weapons of mass destruction and who should be permitted to use them.

Maybe I should order a transcript of this show; there's probably lots more juicy material in there to work with.

UPDATE: Hmm. But then, as Matt tells me, there's the RNEP, a nuclear version of exsting bunker-busters that is apparently being developed. Somehow, though, I suspect that this only makes Schell correct by accident...

UPDATE: Actually Schell talked about the Nuclear Non-Proliferation Treaty, not the ABM treaty; my bad. The stream of the interview is here; the part I was paraphrasing above is between 16:30 and 20:00.

Hey, c'mon, it was from memory.

UPDATE: James Sentman and John Weidner both report having sighted this mystery dialog box. It appears to have nothing to do, behaviorally, with iSync itself; it's just a ghost at this stage.

And a rather poorly worded ghost at that.

Shaykh Ibrahim Mudayris delivers the sermon, which he begins by saying: "O people of Palestine, O steadfast people on the land of beloved Palestine, I know that your hearts are bleeding painfully over what happened in Iraq. I know that your hearts were wounded by the fall of Baghdad, the capital of the caliphate. But, the fall of Iraq does not mean that we will give up our resoluteness and bow to the enemies of God. The quick dramatic events that led to the fall of Baghdad remind us of the Monguls, who entered Baghdad and overwhelmed it in a matter of hours. History repeats itself. That was caused by treason. And today's events smack of treason. But, O God's subjects, it is early to distinguish the traitor from the victim of treason. My fellow preachers and friends blamed some figures for treason and other things. But, I say from here: O people, O God's subject, you must wait until the facts become clear. We are sure that Baghdad was delivered and that it did not surrender. The whole issue smacks of treason. But, was Saddam the head of treason, or was he the victim of this treason?

They said User at the Center features will make it simpler for individual users to personalize their computing experience and to move seamlessly among Macs and other devices. And as a marketing strategy, Panther's User at the Center capabilities are intended to challenge user-centric capabilities of Microsoft Corp.'s Windows XP as well as its forthcoming "Longhorn" client.

In addition, sources said Panther will finally mark the debut of the much-discussed "piles" GUI design concept, which Apple patented in June 2001. According to the patent, piles comprise collections of documents represented graphically in stacks. Users can browse the "piled" documents dynamically by pointing at them with the cursor; the filing system can then divide a pile into subpiles based on each document's content. At the user's request, the filing system can automatically file away documents into existing piles with similar content.

UPDATE: Here's a Flash mock-up of the "piles" concept in action, by Richard Das. Damn, that's cool! I want it!

Thanks to Paul for the tip.