# What identification data is coded onto music CDs? Even homemade ones?
**URL:** https://boards.straightdope.com/t/what-identification-data-is-coded-onto-music-cds-even-homemade-ones/852983
**Category:** Factual Questions
**Created:** [May 1, 2020, 3:03pm UTC](https://boards.straightdope.com/t/what-identification-data-is-coded-onto-music-cds-even-homemade-ones/852983 "2020-05-01T15:03:52Z")
**Posts on this page:** 9
**Page:** 1
### Author:  [@CookingWithGas](https://boards.straightdope.com/u/CookingWithGas)
#### Post date: [May 1, 2020, 3:03pm UTC](https://boards.straightdope.com/t/what-identification-data-is-coded-onto-music-cds-even-homemade-ones/852983/1 "2020-05-01T15:03:52Z")
I am reviewing my old CD collection to see if there are any I have not yet converted to MP3’s. I am using iTunes to do the conversion. I popped in a CD that a friend of mine made that was a compilation of various jazz tunes. Of course, iTunes doesn’t recognize it, so I edited the CD Info. I did not import it, and took it back out to note what songs were on it. When I put it back in I figured I would have to start over, but iTunes recognized it and showed it with the CD title I had entered earlier.
What unique identification data is on a homemade music CD that iTunes can use to recognize it?
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### Author:  [@beowulff](https://boards.straightdope.com/u/beowulff)
#### Post date: [May 1, 2020, 3:09pm UTC](https://boards.straightdope.com/t/what-identification-data-is-coded-onto-music-cds-even-homemade-ones/852983/2 "2020-05-01T15:09:41Z")
No, there is no ID data on the CD.
iTunes just uses the number of tracks and the length of each track to create a “fingerprint” of the CD.
It’s the same method used by CDDB and Gracenote.
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### Author:  [@panache45](https://boards.straightdope.com/u/panache45)
#### Post date: [May 1, 2020, 5:52pm UTC](https://boards.straightdope.com/t/what-identification-data-is-coded-onto-music-cds-even-homemade-ones/852983/3 "2020-05-01T17:52:59Z")
> [@beowulff](#):
>
> No, there is no ID data on the CD.
> iTunes just uses the number of tracks and the length of each track to create a “fingerprint” of the CD.
> It’s the same method used by CDDB and Gracenote.
I have several CDs that are just one long track each. If two of them happened to be the same length, how would iTunes tell them apart?
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### Author:  [@beowulff](https://boards.straightdope.com/u/beowulff)
#### Post date: [May 1, 2020, 5:54pm UTC](https://boards.straightdope.com/t/what-identification-data-is-coded-onto-music-cds-even-homemade-ones/852983/4 "2020-05-01T17:54:51Z")
> [@panache45](#):
>
> I have several CDs that are just one long track each. If two of them happened to be the same length, how would iTunes tell them apart?
It would bring up all the matches and ask you to choose.
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### Author:  [@Musicat](https://boards.straightdope.com/u/Musicat)
#### Post date: [May 1, 2020, 5:57pm UTC](https://boards.straightdope.com/t/what-identification-data-is-coded-onto-music-cds-even-homemade-ones/852983/5 "2020-05-01T17:57:21Z")
> [@beowulff](#):
>
> No, there is no ID data on the CD.
> iTunes just uses the number of tracks and the length of each track to create a “fingerprint” of the CD…
Can you provide a link or reference as proof of that assertion?
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### Author:  [@friedo](https://boards.straightdope.com/u/friedo)
#### Post date: [May 1, 2020, 6:04pm UTC](https://boards.straightdope.com/t/what-identification-data-is-coded-onto-music-cds-even-homemade-ones/852983/6 "2020-05-01T18:04:07Z")
> [@Musicat](#):
>
> Can you provide a link or reference as proof of that assertion?
[Here ya go](https://en.wikipedia.org/wiki/CDDB#How_CDDB_works)
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### Author:  [@Skywatcher](https://boards.straightdope.com/u/Skywatcher)
#### Post date: [May 1, 2020, 6:14pm UTC](https://boards.straightdope.com/t/what-identification-data-is-coded-onto-music-cds-even-homemade-ones/852983/7 "2020-05-01T18:14:00Z")
> [@beowulff](#):
>
> No, there is no ID data on the CD.
> iTunes just uses the number of tracks and the length of each track to create a “fingerprint” of the CD.
> It’s the same method used by CDDB and Gracenote.
iTunes uses the Gracenote database. I know this because submitting CD info to iTunes will result in the message “The CD information was successfully sent to the Gracenote database.”
If Gracenote doesn’t yet know about a particular CD, iTunes will show generic data. I know this because I’ve entered CD info into iTunes.
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### Author:  [@beowulff](https://boards.straightdope.com/u/beowulff)
#### Post date: [May 1, 2020, 6:18pm UTC](https://boards.straightdope.com/t/what-identification-data-is-coded-onto-music-cds-even-homemade-ones/852983/8 "2020-05-01T18:18:00Z")
> [@Skywatcher](#):
>
> iTunes uses the Gracenote database. I know this because submitting CD info to iTunes will result in the message “The CD information was successfully sent to the Gracenote database.”
>
> If Gracenote doesn’t yet know about a particular CD, iTunes will show generic data. I know this because I’ve entered CD info into iTunes.
Yes, I should have mentioned that.
This is why \*so many \*CDs have incorrect track and Artist information - full of typos and just plain wrong data - the first person to submit the data was some kid who couldn’t be bothered to check his entries…
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### Author:  [@BigT](https://boards.straightdope.com/u/BigT)
#### Post date: [May 2, 2020, 12:48am UTC](https://boards.straightdope.com/t/what-identification-data-is-coded-onto-music-cds-even-homemade-ones/852983/9 "2020-05-02T00:48:03Z")
While it is true that most CDs get their info from a database, not from the disk itself, it is actually possible to put the data on the disk. There is something called [CD-Text](https://en.wikipedia.org/wiki/CD-Text) which actually puts data on the disc, which is why you’ll sometimes find standalone (i.e. not internet connected) players that can display track data.
I don’t know much about iTunes, but I did check on Google, and [there is an option called “include CD-Text”](https://discussions.apple.com/thread/668364) that will actually include the disc and track information on the CD itself.
However, based on the previous responses, I suspect this feature is not turned on by default.