Currently Listenbrainz uses MSIDs (Messybrainz-ID) for retrieving useful user stats (e.g. user listens). Now ListenBrainz also plans to generate data which could be used by MusicBrainz to show useful information like artist popularity. MusicBrainz has MBIDs (MusicBrainz-ID) associated with each artist, recording, and release. In order to provide MusicBrainz with the ability to access information based on MBIDs, we have to associate recording_mbids, artist_mbids and release_mbids to the listens where we can. For most of the listens we don’t have artist_mbids and relesae_mbids associated with them. But have recording_mbids associated with them. So, now I plan to associate MBIDs to MSIDs.