======================== unified (from filesystem) ========================
                                         'bitrate'  '128.0'
                                        'duration'  '335'
                                          'artist'  'Ludwig Van Beethoven'
                                     'text_people'  ''
                                         'release'  ''
                                           'title'  'Allegro'
                                           'quals'  ("['Q-HAP-3', 'Q-LOCALNESS-1', 'Q-JZFKS-1', 'Q-UNU-1', 'Q-HHRNBTT-1', "
 "'Q-OLDST-1', 'q-syn-1', 'q-bass-1', 'q-busy-2', 'q-grit-2', 'q-play-2', "
 "'q-chart-3', 'q-drums-1', 'q-other-4', 'q-piano-1', 'q-vocals-1', "
 "'q-mixbeat-1']")
                                      'lastfmtags'  "['instrumental', 'composers', 'romantic', 'classical', 'classic']"
                                     'discogstags'  "['classical']"
                             'musicbrainz_albumid'  ''
                       'musicbrainz_albumartistid'  ''
                            'musicbrainz_artistid'  ''
                             'musicbrainz_trackid'  ''
                                     'tracknumber'  '3'
                                      'tracktotal'  ''
                                            'date'  ''
                                        'comments'  ''
                                           'genre'  'prerock-classical or classical instruments'
                                             'bpm'  '144.233'
                                             'key'  '6A'
                                        'acoustid'  ''
rest: ''

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

'TBPM' (BPM (beats per minute))                     '144.233'
'TCON' (Content type, a.k.a. Genre)                 'prerock-classical or classical instruments'
'TIT2' (Title/songname/content description)         'Allegro'
'TKEY' (Initial key)                                '6A'
'TPE1' (Lead performer(s)/Soloist(s))               'Ludwig Van Beethoven'
'TRCK' (Track number/Position in set)               '3'
'TXXX:Q-HAP'                                        '3'
'TXXX:Q-HHRNBTT'                                    '1'
'TXXX:Q-JZFKS'                                      '1'
'TXXX:Q-LOCALNESS'                                  '1'
'TXXX:Q-OLDST'                                      '1'
'TXXX:Q-UNU'                                        '1'
'TXXX:discogstags'                                  'classical'
'TXXX:lastfmtags'                                   ['instrumental', 'composers', 'romantic', 'classical', 'classic']
'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'                                      '4'
'TXXX:q-piano'                                      '1'
'TXXX:q-play'                                       '2'
'TXXX:q-syn'                                        '1'
'TXXX:q-vocals'                                     '1'
'TXXX:replaygain_track_gain'                        '+1.52 dB'
'TXXX:replaygain_track_peak'                        '0.806886'

========================== row from database ==========================
                                              'id'  200465
                                            'path'  /data/Music/Bulk/00instruments-classical/Beethoven/Beethoven - 03 Allegro.mp3
                                         'working'  None
                                         'bitrate'  128
                                    'duration_sec'  335
                                           'genre'  prerock-classical or classical instruments
                                        'filesize'  5367359
                                           'mtime'  1620561469
                                   'redo_metaread'  0
                                        'rest_str'   00instruments classical 03 prerock classical or classical instruments
                                      'tag_artist'  Ludwig Van Beethoven
                                     'tag_release'  None
                                       'tag_title'  Allegro
                                             'bpm'  144.233
                                    'search_title'  'allegro':1
                                   'search_artist'  'beethoven':3 'ludwig':1 'van':2
                                  'search_release'  
                                     'search_rest'  '00instruments':1 'classical':2 'instruments':5 'or':4 'prerock':3
                                    'search_combo'  '00instruments':5 'allegro':1A 'beethoven':4B 'classical':6 'instruments':9 'ludwig':2B 'or':8 'prerock':7 'van':3B
                                    'tag_tracknum'  3
                                      'num_images'  0
                                             'key'  6A
                                           'quals'  ['Q-HHRNBTT-1', 'q-vocals-1', 'Q-LOCALNESS-1', 'q-piano-1', 'q-mixbeat-1', 'q-play-2', 'Q-OLDST-1', 'Q-UNU-1', 'Q-JZFKS-1', 'q-busy-2', 'q-drums-1', 'q-syn-1', 'q-chart-3', 'q-other-4', 'Q-HAP-3', 'q-bass-1', 'q-grit-2']
                                      'lastfmtags'  ['instrumental', 'composers', 'romantic', 'classical', 'classic']
                                        'tag_date'  
                                     'discogstags'  ['classical']

============================== file details ==============================
                                           'mtime'  1620561468.8118718  (2021-05-09 13:57:48)
                             'size'  5367359