This release improves Classical Release matching plus some other reliability improvements including avoidance of deadlocks
Very Long Song Titles
Classical releases can often have long titles because according to the MusicBrainz Classical Guidelines if they are part of a work they should contain the Work title in each song title, for example here. And Operas should contain each act or scene as in here. This means when matching existing song titles it takes longer because there are more words to match, it is also harder to match because these guidelines don’t reflect as accurately what is written on the cover as for non-classical releases.
Very Large Releases
Because many classical composers catalogues are out of copyright it is inexpensive for music publishers to release large box sets of a composers output. One such example is the 100 CD Complete Works Beethoven release. Its actually too large to show reliably in MusicBrainz so instead I show the results of a search .Trying to match songs to large releases is invariably more time consuming than smaller releases because there are so many permutations to consider, actually expotentially more.
These issues plus other fixes are listed in the Issue Tracker