EMI recently forged a ground-breakingdeal for the consumer by deciding to offer higher bitrate and DRM-free versions of its songsonline. Universal might be about to follow suit.

But every silver lining has its cloud...

In the past, you'd buy into recording artists' worth by accumulating their songs on vinyl. Sure, vinyl isnot the best means of reproduction - audio is compressed, the medium is fragile and after a time, it'll warp, scratch and wear out.

But along came the CD and things changed. We went from 12 inches of vinyl platter to 12 centimetres ofoptical disc. But the boffins at developers Sony and Philips hadn't sold usshort on audio quality.

High-quality music

The original idea was that a single CD would be able to host Beethoven's 9th Symphony, digitally, at such aresolution that the average human could not hear that it's all a lot of little audio slices.

So, we ended up with the RedBook standard. This dictates that a 44.1kHz sample rate at a bit depth of 16bits with a frequency response from a whale-worrying 20Hz to a bat-bothering 20kHz, in stereo, would be sufficient to render even the most dynamic,harmony-rich audio with excellence.

Now hold on to this figure: 1,411.2Kilobits per second (Kbps). That's the data-rate of the Red Book standard.

There were detractors, of course. Some thought the rendition of CD's audio was too clean, while others were miffed that that theycouldn't enjoy vinyl's lavish 1x1ft packaging any more.

The qualms of the latter were allayed with CD-style, multi-page jewel-case booklets and dreamy traycards(more than a few of which, in the early days, listed tracks on sides 1 and 2).So, we had pristine audio with amusing paraphernalia and, though we moanedabout CD prices, we were generally satisfied.

The MP3 revolution

Then along came the internet. At first, there were music enthusiasts desperate to inflict their listeningpreferences on others by making their tracks available online. The internet is a narrow conduit, hence huge stereo music files needed to be compressed in orderto speed transit. The popular compression method was, and still is, MP3.

The dark side we mentioned earlier is here. MP3 compression is not compression as we know it, i.e. by losslessZIP or LZW or RAR. MPEG compression is similar in nature to that ofimage-compression algorithm JPEG.

Lossy compression loses data and in its audio implementation, it discards anything that the codec reckons wecan't hear. The more extreme the compression, the more is lost until such pointas it becomes noticeable - usually warbling in the mid frequencies and loss ofhigh frequencies.

File-sharers didn't mind reduced audio quality, so long as they could more readily swap files with each other.

CD vs. MP3

Meanwhile, record companies were quick to latch on to potential benefits of compression. They could retail128Kbps facsimiles of their artists' output merely by sticking them on a server and charging 70-80p a download. No packaging, just a data exchange - yourcredit card details for a compressed file with, perhaps, a thumbnail image.

Minimal manufacturing,packaging and distribution costs for the record company, and a retail price ona par with what the consumer would pay for a single track from a physical CD album. Great.

The shop price of a tenner for a CD with 12 tracks roughly equates to the iTunes store's per-track price, albeitthat those tracks use the supposedly superior AAC compression format, along with digital-rights management (DRM) that prevents consumers from digitallycopying music to whichever device they wish.

Now, in the light of the EMI/Apple deal, consumers are being asked to pay a premium 99p for tracks thatthey can copy to the backup device of their choice at a compression quality of 256Kbps (double that of the FairPlay-protected 128Kbps tracks).

But some may start asking such questions as: Where's my 1,411.2Kbps Red Book audio? Why do my iTunes trackssound rubbish on my hi-fi? Where's the physical disc, which, in these days of immediate transfer to hard disk, is a robust backup medium in itself?

Unlike the CD, which is a superior medium in so many ways to vinyl and which eventually matched vinyl's retail price, compressed audio offers less in terms of audio quality, less in terms of collectability and we'll soon be charged a premium for being able tocopy it.

Sounds bad, somehow.

Words by: Karl Foster