What happened in Discogs in March 2018?

A new month, so that means that there is a new dumpfile available that I can do analysis on. If this is the first time you see one of these posts I would highly recommend to first read the posts from previous months.

Release statistics

The latest dump ("the April dump") covers the period from March 1 - March 31 (inclusive). The previous dump had 9,554,069 releases, the new dump has 9,680,263 releases. That means 126,194 releases more in the database.

8,962,136 releases stayed the same
589,131 releases were changed
128,996 releases were added
2,802 releases were removed from the database
247 releases had status Draft, Deleted or Rejected
11 releases that were not Accepted were in both dumps
0 release was moved from Draft to Accepted

Luckily this time Discogs did not change the XML format, so it is relatively easy to compare to the previous month. It looks very similar to previous months: the amount of releases edited is very similar, but perhaps with a slight increase (due to more people siging up for Discogs and editing releases).

What I hadn't yet looked at is where the edits are happening: is it mostly older releases that get fixed, or newer releases? I looked at the numbers of the releases that were changed and plotted the following barchart:

Releases in Discogs that were changed in March 2018

As can be seen the changes are spread pretty evenly across the data, although significantly more older releases are being changed. I had expected those to be more stable. On the other hand: in the last year or so quite a few new fields were introduced so it could be that the older releases are "catching up" with the new standards.

Smells

The amount of releases with smells that were added in March 2018: 1,862 releases, with around 8,000+ errors. This is a bit more than in previous months, but my scripts are also catching more errors. It should be noted that tracklisting errors were ignored.

For the rest it is very dull: around 90 depósito legal errors, a bit more than 100 SPARS code issues, more than 1200 label code errors, some 200 rights society errors, and so on.

It all looks very normal and that is also something that frustrates me, as most of these errors are completely preventable. It makes me wonder if Discogs actually is really interested in having these errors fixed in a structural way, or if "outsourcing" fixing errors to the contributors is their preferred way.

Comments

SID codes (part 1)

One thing that I only learned about after using Discogs is the so called Source Identification Code, or SID. These codes were introduced in 1994 to combat piracy and to find out on which machines a CD was made. It was introduced by Philips and adopted by IFPI, and specifications are publicly available which clearly describe the two available SID codes (mastering SID code and mould SID code). Since quite a few months Discogs has two fields available in the " Barcode and Other Identifiers " (BaOI) section: Mould SID code Mastering SID code A few questions immediately popped up in my mind: how many releases don't have a SID field defined when there should be (for example, the free text field indicates it is a SID field)? how many releases have a SID field with values that should not be in the SID field? how many release have a SID field, but a wrong year (as SID codes were only introduced in 1994) how many vinyl releases have a SID code defined (which is impossi...

SPARS codes (part 1)

Let's talk about SPARS codes used on CDs (or CD-like formats). You have most likely seen it used, but maybe don't know its name. The SPARS code is a three letter code indicating if recording, mixing and mastering were analogue or digital. For example they could look like the ones below. There is not a fixed format, so there are other variants as well. Personally I am not paying too much attention to these codes (I simply do not care), but in the classical music world if something was labeled as DDD (so everything digital) companies could ask premium prices. That makes it interesting information to mine and unlock, which is something that Discogs does not allow people to do when searching (yet!) even though it could be a helpful filter. I wanted to see if it can be used as an identifier to tell releases apart (are there similar releases where the only difference is the SPARS code?). SPARS code in Discogs Since a few months SPARS is a separate field in the Discogs ...

Using matrix numbers of CDs to verify release years (1)

One of the first steps when making CDs is to produce a "glass master". From that (using a few more steps) a "stamper" is created which is then used to press the actual CDs. When looking at a CD you can often see text in a ring in the middle of the CD. This is the so called matrix which comes from the glass master. Apart from the matrix other text (like the IFPI mastering SID code) could possibly also come from the glass master. A bit of background information can be found on page 7 of the IFPI SID code implementation guide although I would also highly recommend watching some of the clips about glass masters on YouTube, which are highly informative. One company making a lot of these glass masters is Cinram . For most of their glass masters they stored the production date in matrix. This is good news, because it means that it could possibly be used to verify releases and see if the declared year of the release is right: it could never have been released before...

Vinyl & Data

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