Attribute "Isrc" in a song no more returned

Hi blackarcanis

Can you specify which songs exactly were missing ISRC? I see this on all songs I have tried for example this one below

https://api.music.apple.com/v1/catalog/us/songs/1477058176

@_jb

It's happening when you are retrieving tracks list from a playlist or from library of the user. When tracks are in a "list", the "isrc" field is no more returned.

Hi, yes we cannot determine the ISRC for a library song since those are often user uploaded songs.

Here is the documentation for a library song
https://developer.apple.com/documentation/applemusicapi/librarysong/attributes

I completely understand that for library tracks, if uploaded by the user.
But I'm talking about "Apple Music tracks" here, these tracks from the Apple Music catalog directly.

For example; I create a playlist on Apple Music. Then go in Apple Music catalog and add a track to this playlist.
When then I'm retrieving this playlist tracklist with the Apple Music API, the ISRC field is empty while it's an Apple Music track.

The issue is about why these Apple Music tracks (and not tracks uploaded by users) don't have any more the ISRC field ?

if the "type" in the response is library-songs we don't have an ISRC field unfortunately. Once you add a song to your playlist, it adds a new library song. Even though these are Apple Music songs, anything added to your library will be a library-song. Am I correct is saying you are seeing this on library-songs resources?

To solve this problem, we have a relationship on the library-songs called "catalog" which you can request like

api.music.apple.com/v1/me/library/songs/{library-id}?include=catalog

if the library-song has a catalog counterpart, this should come back and that catalog song will have the ISRC.

Let me know if that helps.