Apropos the discussion above and at Please help me grab "recorded at", it appears that there are a great many potential attributes of recording. To see these, look at https://musicbrainz.org/relationships and the entries for the “Recording” row. There are so many that I doubt I will be able to do more than scratch the surface. If anyone has any particular requests (other than the already-requested ‘recorded at’ which is part of Place-Recording), please let me know.