======================== unified (from filesystem) ========================
                                         'bitrate'  '112.0'
                                        'duration'  '600'
                                          'artist'  'Schubert'
                                     'text_people'  ''
                                         'release'  'Schubert - 4 Impromptus d 899'
                                           'title'  'C mineur'
                                           'quals'  ("['Q-HAP-3', 'Q-LOCALNESS-1', 'Q-JZFKS-1', 'Q-UNU-1', 'Q-HHRNBTT-1', "
 "'Q-OLDST-1', 'q-syn-1', 'Q-PLAY-3', 'q-bass-1', 'q-busy-2', 'q-grit-2', "
 "'Q-PIANO-4', 'q-chart-3', 'q-drums-1', 'q-other-1', 'q-vocals-1', "
 "'q-mixbeat-1']")
                                      'lastfmtags'  "['classical', 'romantic', 'piano', 'composers', 'instrumental']"
                                     'discogstags'  "['electronic']"
                             'musicbrainz_albumid'  ''
                       'musicbrainz_albumartistid'  ''
                            'musicbrainz_artistid'  ''
                             'musicbrainz_trackid'  ''
                                     'tracknumber'  '1'
                                      'tracktotal'  ''
                                            'date'  ''
                                        'comments'  ''
                                           'genre'  'prerock-classical or classical instruments'
                                             'bpm'  '91.6'
                                             'key'  '6A'
                                        'acoustid'  ''
rest: ''

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

'TALB' (Album/Movie/Show title)                     'Schubert - 4 Impromptus d 899'
'TBPM' (BPM (beats per minute))                     '91.6'
'TCON' (Content type, a.k.a. Genre)                 'prerock-classical or classical instruments'
'TIT2' (Title/songname/content description)         'C mineur'
'TKEY' (Initial key)                                '6A'
'TPE1' (Lead performer(s)/Soloist(s))               'Schubert'
'TRCK' (Track number/Position in set)               '1'
'TXXX:Q-HAP'                                        '3'
'TXXX:Q-HHRNBTT'                                    '1'
'TXXX:Q-JZFKS'                                      '1'
'TXXX:Q-LOCALNESS'                                  '1'
'TXXX:Q-OLDST'                                      '1'
'TXXX:Q-PIANO'                                      '4'
'TXXX:Q-PLAY'                                       '3'
'TXXX:Q-UNU'                                        '1'
'TXXX:discogstags'                                  'electronic'
'TXXX:lastfmtags'                                   ['classical', 'romantic', 'piano', 'composers', 'instrumental']
'TXXX:q-bass'                                       '1'
'TXXX:q-busy'                                       '2'
'TXXX:q-chart'                                      '3'
'TXXX:q-drums'                                      '1'
'TXXX:q-grit'                                       '2'
'TXXX:q-mixbeat'                                    '1'
'TXXX:q-other'                                      '1'
'TXXX:q-syn'                                        '1'
'TXXX:q-vocals'                                     '1'
'TXXX:replaygain_track_gain'                        '+2.09 dB'
'TXXX:replaygain_track_peak'                        '0.850965'

========================== row from database ==========================
                                              'id'  1213718
                                            'path'  /data/Music/Bulk/00instruments-classical/Schubert/Schubert - 4 Impromptus d 899/1._c_mineur.mp3
                                         'working'  None
                                         'bitrate'  112
                                    'duration_sec'  600
                                           'genre'  prerock-classical or classical instruments
                                        'filesize'  8402746
                                           'mtime'  1620574224
                                   'redo_metaread'  0
                                        'rest_str'   00instruments classical 1._c_mineur prerock classical or classical instruments
                                      'tag_artist'  Schubert
                                     'tag_release'  Schubert - 4 Impromptus d 899
                                       'tag_title'  C mineur
                                             'bpm'  91.6
                                    'search_title'  'c':1 'mineur':2
                                   'search_artist'  'schubert':1
                                  'search_release'  '4':2 '899':5 'd':4 'impromptus':3 'schubert':1
                                     'search_rest'  '00instruments':1 '1':3,6 'c':4,7 'classical':2 'instruments':11 'mineur':5,8 'or':10 'prerock':9
                                    'search_combo'  '00instruments':9 '1':11,14 '4':5C '899':8C 'c':1A,12,15 'classical':10 'd':7C 'impromptus':6C 'instruments':19 'mineur':2A,13,16 'or':18 'prerock':17 'schubert':3B,4C
                                    'tag_tracknum'  1
                                      'num_images'  0
                                             'key'  6A
                                           'quals'  ['Q-HHRNBTT-1', 'q-vocals-1', 'Q-LOCALNESS-1', 'q-mixbeat-1', 'Q-PIANO-4', 'Q-OLDST-1', 'Q-UNU-1', 'Q-JZFKS-1', 'q-busy-2', 'q-drums-1', 'q-syn-1', 'q-chart-3', 'q-other-1', 'Q-HAP-3', 'Q-PLAY-3', 'q-bass-1', 'q-grit-2']
                                      'lastfmtags'  ['classical', 'romantic', 'piano', 'composers', 'instrumental']
                                        'tag_date'  
                                     'discogstags'  ['electronic']

============================== file details ==============================
                                           'mtime'  1620574224.3891282  (2021-05-09 17:30:24)
                             'size'  8402746