From: dmhills{at}attglobal.net (Don Hills)

In article , John Beckett
 wrote:
>
>My first hint of magic came when I started WMP and it offered to play a
>Beethoven sample. How did it know that I would like that!?

Gracenote CDDB (http://www.gracenote.com) or similar site.

>Then, after a couple of days (and playing the two music CDs), I am amazed
>to see that WMP has learnt details of the CD (it doesn't get any better
>than Schubert piano impromptus played by Rudolf Buchbinder).

Same answer.

>I vaguely recall a year or two ago seeing that WMP could search for stuff
>on the Internet, but HOW is it possible for it to identify two really old
>music CDs?
>
>I guess there is a serial number encoded on a CD, even old CDs - a fairly
>boring explanation.

More boring than that. There is an ISRC code on most discs, but some CDROM
drives can't read it. Instead, an application collects details from the
CD's Table Of Contents: number of tracks and the length of each track in
minutes and seconds. This is a fairly unique combination of numbers. It
creates a "hash" (short unique number) from the info and sends it
to Gracenote or similar. The hash is then used to look up a database record
that contains the details of the CD. If you pick a really new, or really
obscure, or home-made compilation CD, you may find it doesn't know the
details. With many apps, you have the option of entering the info yourself
for local storage and optionally for forwarding to the CD DB site to update
their database.

>I recently read about Parsons Code to identify a tune from an amazingly
>small amount of information by specifying (for only 10 or 20 notes)
>whether the notes go up or down wrt to each other. Naturally I found this
>in a Richard Dawkins book where he was explaining a similar procedure for
>measuring the age of wooden objects from the patterns in the tree rings (a
>sequence of wider or narrower rings).

The local telco here offer a Song ID service to mobile phone users: Dial
the service, then hold the phone as close as possible to the source of the
music for 30 seconds and it will text message you back the track details.
http://www.telecom.co.nz/content/0,3900,204595-201463,00.html
Apparently it has a database of over 2.6 million tracks...

--
Don Hills    (dmhills at attglobaldotnet)     Wellington, New Zealand
"New interface closely resembles Presentation Manager,
 preparing you for the wonders of OS/2!"
    -- Microsoft advertisement on the box for Windows 2.11 for 286

--- BBBS/NT v4.01 Flag-5