I added quite a lot of ISRCs over the last weeks. Before adding them to a release, I usually check for existing ones. Personally I don’t like to add a different ISRC to an existing recording. So I am not happy about examples like this: http://musicbrainz.org/recording/10cfdacf-53c3-4662-b216-62046e318f6e
According to the Style guidelines, recordings with different mastering should not be separated. The guidelines for edits are less straightforward. Should we merge similar edits if they are only distinguishable by ISRC?
Edits generally count as a different mix, and they can all be kept separate (and linked to the original with an “edit of” relationship, if the original is known). But for remasters that get a new ISRC, we do add multiple ISRCs to the recording, yes. At first I worried about it not being clean myself, but then I found out that multiple ISRCs for the same master are a relatively common thing anyway (because the music industry is how it is…) so I stopped worrying
In my experience it is very common that the verifyable exact same recording gets assigned a new ISRC on a later release. I guess the people putting the releases together often don’t care too much and we have to live with that. There is a reason the schema allows multiple ISRCs per recording, even though in a perfect world it wouldn’t be necessary
