======================== unified (from filesystem) ========================
                                         'bitrate'  '128.0'
                                        'duration'  '659'
                                          'artist'  '[unknown]'
                                     'text_people'  ''
                                         'release'  ''
                                           'title'  'Ca Dao'
                                           'quals'  ("['Q-OLDST-2', 'Q-JZFKS-1', 'Q-UNU-1', 'Q-LOCALNESS-2', 'Q-HHRNBTT-1', "
 "'q-syn-1', 'q-bass-1', 'q-busy-3', 'q-grit-2', 'q-play-2', 'q-chart-2', "
 "'q-drums-1', 'q-other-2', 'q-piano-1', 'q-vocals-4', 'q-mixbeat-1']")
                             'musicbrainz_albumid'  ''
                       'musicbrainz_albumartistid'  ''
                            'musicbrainz_artistid'  ''
                             'musicbrainz_trackid'  ''
                                     'tracknumber'  ''
                                      'tracktotal'  ''
                                            'date'  ''
                                        'comments'  ''
                                           'genre'  'loc-unsorted'
                                             'bpm'  '135.004'
                                             'key'  '6A'
                                        'acoustid'  ''
rest: ''

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

'TBPM' (BPM (beats per minute))                     '135.004'
'TCON' (Content type, a.k.a. Genre)                 'loc-unsorted'
'TIT2' (Title/songname/content description)         'Ca Dao'
'TKEY' (Initial key)                                '6A'
'TPE1' (Lead performer(s)/Soloist(s))               '[unknown]'
'TXXX:Mp3gain_minmax'                               '145,208'
'TXXX:Mp3gain_undo'                                 '+002,+002,N'
'TXXX:Q-HHRNBTT'                                    '1'
'TXXX:Q-JZFKS'                                      '1'
'TXXX:Q-LOCALNESS'                                  '2'
'TXXX:Q-OLDST'                                      '2'
'TXXX:Q-UNU'                                        '1'
'TXXX:q-bass'                                       '1'
'TXXX:q-busy'                                       '3'
'TXXX:q-chart'                                      '2'
'TXXX:q-drums'                                      '1'
'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'                        '+0.89 dB'
'TXXX:replaygain_track_peak'                        '0.800473'

========================== row from database ==========================
                                              'id'  343428
                                            'path'  /data/Music/Bulk/00localcharacter/Ca Dao： Vietnamese Folk Poems (1971-72) (UbuWeb)/mp3 [128k-160k]/ca-dao.mp3
                                         'working'  None
                                         'bitrate'  128
                                    'duration_sec'  659
                                           'genre'  loc-unsorted
                                        'filesize'  10557441
                                           'mtime'  1620400740
                                   'redo_metaread'  0
                                        'rest_str'   00localcharacter Dao： Vietnamese Folk Poems (1971 72) (UbuWeb) mp3 [128k 160k] ca dao loc unsorted
                                      'tag_artist'  [unknown]
                                     'tag_release'  None
                                       'tag_title'  Ca Dao
                                             'bpm'  135.004
                                    'search_title'  'ca':1 'dao':2
                                   'search_artist'  'unknown':1,2
                                  'search_release'  
                                     'search_rest'  '128k':14,15 '160k':16,17 '1971':7,8 '72':9,10 'ca':18 'dao':1,2,3 'folk':5 'loc':19 'mp3':13 'poems':6 'ubu':21,22 'ubuweb':11,12 'unsorted':20 'vietnamese':4 'web':23,24
                                    'search_combo'  '128k':18,19 '160k':20,21 '1971':11,12 '72':13,14 'ca':1A,22 'dao':2A,5,6,7 'folk':9 'loc':23 'mp3':17 'poems':10 'ubu':25,26 'ubuweb':15,16 'unknown':3B,4B 'unsorted':24 'vietnamese':8 'web':27,28
                                    'tag_tracknum'  None
                                      'num_images'  0
                                             'key'  6A
                                           'quals'  ['Q-HHRNBTT-1', 'q-vocals-4', 'Q-LOCALNESS-2', 'q-piano-1', 'q-mixbeat-1', 'q-play-2', 'Q-OLDST-2', 'Q-UNU-1', 'Q-JZFKS-1', 'q-busy-3', 'q-drums-1', 'q-syn-1', 'q-chart-2', 'q-other-2', 'q-bass-1', 'q-grit-2']
                                      'lastfmtags'  ['mysterious', 'unknown', 'all', 'mistagged artist', 'rock']
                                        'tag_date'  
                                     'discogstags'  []

============================== file details ==============================
                                           'mtime'  1620400740.2556195  (2021-05-07 17:19:00)
                             'size'  10557441