python3-mb: do not always use "and" to concatenate performer instruments about jack HOT 5 CLOSED

please test.

from jack.

Almost.

It used to be

PERFORMER=John Acock (harmonium and mellotron and piano)
PERFORMER=Phil Collins (guest and membranophone and percussion and vibraphone and additional)
PERFORMER=John Hackett (bell and flute and guest and synthesizer)
PERFORMER=Steve Hackett (acoustic guitar and autoharp and bell and electric guitar and harmonium and mellotron and vocals)
PERFORMER=Robin Miller (cor anglais and oboe)
PERFORMER=Mike Rutherford (12 string guitar and bass guitar and bass pedals and guest)
PERFORMER=Nigel Warren-Green (cello and solo)

Now it is

PERFORMER=John Acock (harmonium, mellotron, and piano)
PERFORMER=Phil Collins (guest, membranophone, percussion, vibraphone, and additional)
PERFORMER=John Hackett (bell, flute, guest, and synthesizer)
PERFORMER=Steve Hackett (acoustic guitar, autoharp, bell, electric guitar, harmonium, mellotron, and vocals)
PERFORMER=Robin Miller (cor anglais and oboe)
PERFORMER=Mike Rutherford (12 string guitar, bass guitar, bass pedals, and guest)
PERFORMER=Nigel Warren-Green (cello and solo)

Note the comma before "and", which is why MusicBrainz Picard still does not flag this file as perfectly tagged.

from jack.

better now?

from jack.

Perfect!

But sadly still different from how Picard would tag the same release.
Apparently, vocals and instruments need to be grouped separately, which makes sense.
Vocals need the word "vocals" as a suffix.
Also, "guest" and "additional" need to be the first word, and not be followed by a comma.
Ideally leading to
PERFORMER=Phil Collins (additional vocals)
PERFORMER=Phil Collins (guest membranophone, percussion and vibraphone)
Of course this all has nothing to do with the human_readable_list function which works as it should,
but rather with the MusicBrainz data parsing.

Thanks for making me read https://en.wikipedia.org/wiki/Ofxord_comma !

from jack.

Closing, the performer grouping is a separate issue.

from jack.