======================== unified (from filesystem) ========================
                                         'bitrate'  '200.871'
                                        'duration'  '127'
                                          'artist'  'The Statler Brothers'
                                     'text_people'  ''
                                         'release'  'Gold'
                                           'title'  'Who Am I to Say?'
                                           'quals'  ("['Q-HAP-3', 'Q-JZFKS-1', 'Q-UNU-2', 'Q-OLDST-1', 'Q-HHRNBTT-1', "
 "'Q-LOCALNESS-3', 'q-syn-1', 'q-bass-1', 'q-busy-2', 'q-grit-2', 'q-play-2', "
 "'q-chart-3', 'q-drums-2', 'q-other-2', 'q-piano-1', 'q-vocals-4', "
 "'q-mixbeat-1']")
                                      'lastfmtags'  "['soundtrack', 'country', 'rock', 'oldies', 'classic country']"
                                     'discogstags'  "['country', 'folk, world, & country']"
                             'musicbrainz_albumid'  ''
                       'musicbrainz_albumartistid'  ''
                            'musicbrainz_artistid'  ''
                             'musicbrainz_trackid'  ''
                                     'tracknumber'  '16'
                                      'tracktotal'  ''
                                            'date'  '1960'
                                        'comments'  ''
                                           'genre'  'loc-namerica-country-classic'
                                             'bpm'  '92.602'
                                             'key'  '4B'
                                        'acoustid'  ''
rest: ''

======================== rawer (from filesystem) ========================

'TALB' (Album/Movie/Show title)                     'Gold'
'TBPM' (BPM (beats per minute))                     '92.602'
'TCON' (Content type, a.k.a. Genre)                 'loc-namerica-country-classic'
'TDRC' (Recording time)                             '1960'
'TIT2' (Title/songname/content description)         'Who Am I to Say?'
'TKEY' (Initial key)                                '4B'
'TPE1' (Lead performer(s)/Soloist(s))               'The Statler Brothers'
'TRCK' (Track number/Position in set)               '16'
'TXXX:Q-HAP'                                        '3'
'TXXX:Q-HHRNBTT'                                    '1'
'TXXX:Q-JZFKS'                                      '1'
'TXXX:Q-LOCALNESS'                                  '3'
'TXXX:Q-OLDST'                                      '1'
'TXXX:Q-UNU'                                        '2'
'TXXX:discogstags'                                  ['country', 'folk, world, & country']
'TXXX:lastfmtags'                                   ['soundtrack', 'country', 'rock', 'oldies', 'classic country']
'TXXX:q-bass'                                       '1'
'TXXX:q-busy'                                       '2'
'TXXX:q-chart'                                      '3'
'TXXX:q-drums'                                      '2'
'TXXX:q-grit'                                       '2'
'TXXX:q-mixbeat'                                    '1'
'TXXX:q-other'                                      '2'
'TXXX:q-piano'                                      '1'
'TXXX:q-play'                                       '2'
'TXXX:q-syn'                                        '1'
'TXXX:q-vocals'                                     '4'
'TXXX:replaygain_track_gain'                        '+2.36 dB'
'TXXX:replaygain_track_peak'                        '0.597196'

========================== row from database ==========================
                                              'id'  1259723
                                            'path'  /data/Music/Bulk/00localcharacter/The Statler Brothers/116-the_statler_brothers-who_am_i_to_say.mp3
                                         'working'  None
                                         'bitrate'  200
                                    'duration_sec'  127
                                           'genre'  loc-namerica-country-classic
                                        'filesize'  3196626
                                           'mtime'  1621629830
                                   'redo_metaread'  0
                                        'rest_str'   00localcharacter 116 the_statler_brothers who_am_i_to_say loc namerica country classic
                                      'tag_artist'  The Statler Brothers
                                     'tag_release'  Gold
                                       'tag_title'  Who Am I to Say?
                                             'bpm'  92.602
                                    'search_title'  'am':2 'i':3 'say':5 'to':4 'who':1
                                   'search_artist'  'brothers':3 'statler':2 'the':1
                                  'search_release'  'gold':1
                                     'search_rest'  '116':1 'am':6 'brothers':4 'classic':13 'country':12 'i':7 'loc':10 'namerica':11 'say':9 'statler':3 'the':2 'to':8 'who':5
                                    'search_combo'  '116':10 'am':2A,15 'brothers':8B,13 'classic':22 'country':21 'gold':9C 'i':3A,16 'loc':19 'namerica':20 'say':5A,18 'statler':7B,12 'the':6B,11 'to':4A,17 'who':1A,14
                                    'tag_tracknum'  16
                                      'num_images'  0
                                             'key'  4B
                                           'quals'  ['Q-HHRNBTT-1', 'q-vocals-4', 'Q-LOCALNESS-3', 'q-piano-1', 'q-mixbeat-1', 'q-play-2', 'Q-OLDST-1', 'Q-UNU-2', 'Q-JZFKS-1', 'q-busy-2', 'q-drums-2', 'q-syn-1', 'q-chart-3', 'q-other-2', 'Q-HAP-3', 'q-bass-1', 'q-grit-2']
                                      'lastfmtags'  ['soundtrack', 'country', 'rock', 'oldies', 'classic country']
                                        'tag_date'  1960
                                     'discogstags'  ['country', 'folk, world, & country']

============================== file details ==============================
                                           'mtime'  1621629829.5596821  (2021-05-21 22:43:49)
                             'size'  3196626