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On the word "recording"

I agree with mudcrow. To me the word "recording" will always mean the original act of performance/recording, as in "what year did the Rutles record their first album?"

On the number of levels

I agree with reosarevok. Further levels should only be created if doing so won't create (even more) confusion.

caller#6's use case

An example:

Miles Davis recorded 'round Midnight 35 times.[1]

MB currently has 136 "recordings" of 'round Midnight by Miles Davis. [2]

I might have the time to add all the performance ARs to the 35 session/recordings before I die. I definitely will never have time to add duplicates for each of the remaining 101 tracks.

This is not an edge case in Jazz.

As a MusicBrainz user, I'm interested in finding the 35 session/performance/recordings. If I need to know which releases have decent audio-quality, I'll check the amazon reviews.