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ISRC codes in Discogs (part 3)

Time to revisit the ISRC codes. I already talked about these twice, namely how many errors for these codes there are in Discogs, as well as how to extract them from a CD.

In the first of those posts I already hinted at that there is actually a year component in the ISRC codes. The ISRC code for a single track has 12 characters. Characters 6 and 7 should be digits indicating the year the code was assigned (although in the early days some ISRC codes were handed out where the year the song was written or when the recording was made). It would of course been easier if they would have used 4 characters, but they didn't.

That means that the year component from the ISRC code can be used to check whether or not a release is correctly dated, because a release cannot be from earlier than the year the ISRC was assigned.

I adapted my scripts to check for a few things:
  • is the format confirming to the ISRC standard?
  • is the year recorded in the ISRC not later than the date of the release?
The latter could indicate a few things: wrong release date, mistake in the ISRC, or mistake when entering the data.

I only looked at the entries where ISRC fields were very clearly marked using the ISRC field. As shown in earlier blog posts there are still some 55,000 other entries where this needs to be fixed. These have not been looked at.

For this blog post I looked at 18550 releases with in total 45446 ISRC codes. Of these I could find 676 ISRC codes with an error, in 280 releases (my guess is that when looking at the other 55,000 releases as well these numbers will likely triple). In Discogs they are distributed as follows:

Distribution of releases with wrong ISRC fields
Of these 7 releases (with 8 ISRC codes) were not confirming to the format. As it turned out a few of these actually described a range of ISRC codes and were meant for the entire release (another reason to try to record the ISRC codes with the tracks). Others were errors, where for example 'O' (capital o) was used instead of '0' (zero).

The other releases (273 individual releases with 668 ISRC codes) had an error where the release year was earlier than the year stored in the ISRC. For a handful of these I already confirmed that it was in fact a data entry error, but I still need to look at the others.

Personally I think that this check is quite effective and I am happy with the results.

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