Barcode

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Definition

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 many different types of barcode but the usual ones are Global Trade Item Numbers (GTINs). The most common types of GTIN are:

  • Universal Product Code (UPC), which is the original barcode used in North America. They are 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.
  • European Article Number (EAN) also known as Japanese Article Number (JAN), which is widely used in the rest of the world. The 13 digit type (EAN-13) is the most common, although there are others such as EAN-8. A UPC can be turned into an EAN-13 by adding a leading zero.

Finding

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.

Googling

  • "artist name"+"release name"+"EAN"/"UPC"/"JAN"
  • <Amazon ASIN>+"EAN"/"UPC"/"JAN"
  • <catalog number>+"EAN"/"UPC"/"JAN"

Guessing

  • 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.
  • Amazon Matching 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! :-)

Other Identifiers

Also see http://www.iasa-web.org/icat/08_0.htm for some others.

Resources

Barcode generator