By Dave on September 15, 2008
Quite by accident, I discovered something new about iTunes today; it can identify music on a CD that you burn from vinyl, seemingly by way of magic.
Over the weekend I was talking with a friend about some of the music we listened to years ago, and I offered to lend him some that I thought he’d enjoy. I was digging through some of my old LP’s and cassette tapes yesterday, and on a whim decided to digitize a few of the albums and put them on CD — he doesn’t have a turntable, and it’d been a while since I’d listened to them & thought it’d be nice to listen in the car.
I used one of those CD’s today — not exactly CD-quality, recorded as it was from an album that was cut in 1981 — but it worked great (and it’s almost scary to realize that I still knew the lyrics word for word!) I brought the CD in the house this evening, and my son was wondering what it sounded like, so I popped it into my wife’s kitchen computer (an old Mac laptop) so we could listen. Much to our amazement, once iTunes fired up, the album name and song titles were right there!
Now keep in mind that this CD started out from a dusty 27-year-old LP, played on a not-very-well-kept turntable. The turntable is connected to a receiver, which has a patch cable with an 1/8” stereo plug connected to the mic input on my computer; pure analog. The analog audio was digitized using a shareware audio editing app (Amadeus II) and saved out to a plain vanilla aiff file, then burned to a CD-R with Toast. I didn’t go to the trouble of naming any of the tracks, nor did I do anything to help the computer identify the music, much less take the time to clean up the LP’s hiss & pop from the audio. But in the time it took to launch iTunes on a 233MHz G3 PowerBook, it was able to sample the music on the CD, connect with Gracenote CDDB and match those samples to the entry in their database. Wow.
The magic happens via the Gracenote Recognition service:
As a recognition service, we… enable… applications to access our database and recognition services. On most commercial music compact discs, there is no disc title, artist, track title, credits, or other information that a player running on your computer can extract and display for you.
… However, a licensed application can lookup the CD in the database and return the title and track information to the application for display by the time you hear the first notes of the album.
I understand the basic mechanics of what’s going on, but it just floors me that it can happen so fast. I’ve seen iTunes identify CD’s before, but they were all commercial disks, and just figured that there was something digitally encoded on the disk that helped iTunes and Gracenote know what was on it. I’ve also used my Verizon Razr V3’s V-Cast Song ID app a number of times, but that has to “listen” for 10 seconds, then has to think about it a little before it can identify a song. But iTunes did an entire CD in a matter of three or four seconds.
While it’s not exactly magic, the way it works is still pretty magical, don’t you think?