Barcodes are machine-readable numbers used as stock control mechanisms by retailers: as such they are highly standardised and well recognised, and form an invaluable identifier for communication between companies.
There are a few different types. Some of the most common are:
- Universal Product Code (UPC)
- This was the original barcode introduced in the US. They are theoretically 12 digits long, but any number of zeros at the start can be left off, so the actual printed barcode can be shorter than this. Wikipedia page
- European Article Number (EAN)
- This is the European version, and is basically the same as the UPC but has 13 digits. All UPCs are also valid EANs, they just have an extra zero at the start. Somewhere, not sure where, I got the impression that the US is also standardising on EANs now. Wikipedia page EAN is also used in Japan under the name of Japan Article Number (JAN). The country codes for japanese products being 49 and 45. Wikipedia pages: ja, en
You're in luck if you have the physical media and there's a barcode printed on it. When doing research on releases you don't own, it's often hard to find the right UPC/EAN. Here are some tips to help you out.
- "artist name"+"release name"+"EAN"/"UPC"/"JAN"
- <Amazon ASIN>+"EAN"/"UPC"/"JAN"
- <catalog number>+"EAN"/"UPC"/"JAN"
- Many western labels use parts of barcodes for catalog numbers, or rather catalog numbers in barcodes.
- The last digit is always the checksum. You can easily calculate it using an on-line tool.
- The digit just before the checksum often stands for media type. E.g. many EMI sublabels often use these: 1 - LP, 2 - CD, 4 - MC, 6 - 12" vinyl, 7 - 7" vinyl, 8 - MD. If you have one barcode, you can try changing the type digit, recalculating the check digit and googling for the new barcode. But also note that different media types sometimes contain different track lists. E.g. LPs are sometimes shorter than CDs.
- If all you have is a catalog number, and you think it's part of a barcode, look for releases from the same years, artist and/or label with similar numbers. You'll often find many releases have the same barcode prefix, so all you'll have to do is prepend the prefix to the catalog number, add the type digit (if needed), calculate the check digit - and you're done.
Reasons for Adding Barcodes
I think it's worth recording these, just so we know why we're doing what we're doing:
- Barcodes are an industry standard for identifying products. Adding barcodes makes the MusicBrainz data much more accessible and useful for a variety of organisations, from wholesalers and retailers to public libraries. Some of them might be prepared to license the MusicBrainz database.
- Barcodes are clear, visually distinct, well recognised, and almost ubiquitous. This makes them a really useful way to help amateur cataloguers be precise about exactly what they are talking about, even if they don't understand the full subtleties of re-releases, regional variations, catalog numbers, and so on.
- AmazonMatching would be made far easier if barcodes were available. Adding a barcode to an album would, pretty much automatically, result in MusicBrainz acquiring an ASIN as well. This adds cover-art to album pages, and earns MusicBrainz money through referral fees.
- You can buy USB barcode scanners for not much money. This would be a nice way to manage large collections of music. For example, a music collector buys a job lot of old CDs at a jumble sale, and wants to add them all to their private catalog. OK, maybe not a very common requirement, but I thought I'd throw it in there! :-)
- LabelCode (Note: for labels, not albums)
- ISRC for recordings (single tracks)
Also see http://www.iasa-web.org/icat/08_0.htm for some others.