======================== unified (from filesystem) ========================
                                         'bitrate'  '256.0'
                                        'duration'  '237'
                                          'artist'  'Frederic Chopin'
                                     'text_people'  ''
                                         'release'  'Romantic Piano Music (Disk 2)'
                                           'title'  'Waltz, Grande valse Op. 42 A flat major'
                                           'quals'  ("['Q-HAP-2', 'Q-LOCALNESS-1', 'Q-JZFKS-1', 'Q-UNU-1', 'Q-HHRNBTT-1', "
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                                      'lastfmtags'  "['classical', 'piano', 'romantic', 'polish', 'instrumental']"
                             'musicbrainz_albumid'  ''
                       'musicbrainz_albumartistid'  ''
                            'musicbrainz_artistid'  ''
                             'musicbrainz_trackid'  ''
                                     'tracknumber'  '2'
                                      'tracktotal'  '21'
                                            'date'  '1993'
                                        'comments'  ''
                                           'genre'  'prerock-classical or classical instruments'
                                             'bpm'  '145.1'
                                             'key'  '4B'
                                        'acoustid'  ''
rest: ''

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

'TALB' (Album/Movie/Show title)                     'Romantic Piano Music (Disk 2)'
'TBPM' (BPM (beats per minute))                     '145.1'
'TCON' (Content type, a.k.a. Genre)                 'prerock-classical or classical instruments'
'TDRC' (Recording time)                             '1993'
'TIT2' (Title/songname/content description)         'Waltz, Grande valse Op. 42 A flat major'
'TKEY' (Initial key)                                '4B'
'TPE1' (Lead performer(s)/Soloist(s))               'Frederic Chopin'
'TRCK' (Track number/Position in set)               '2/21'
'TSSE' (Software/Hardware and settings used for encoding)  'Audiograbber 1.83.01, LAME dll 3.97, 256 Kbit/s, Joint Stereo, Normal quality'
'TXXX:Q-HAP'                                        '2'
'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:lastfmtags'                                   ['classical', 'piano', 'romantic', 'polish', 'instrumental']
'TXXX:q-bass'                                       '1'
'TXXX:q-busy'                                       '3'
'TXXX:q-chart'                                      '3'
'TXXX:q-drums'                                      '1'
'TXXX:q-grit'                                       '1'
'TXXX:q-mixbeat'                                    '1'
'TXXX:q-other'                                      '1'
'TXXX:q-syn'                                        '1'
'TXXX:q-vocals'                                     '1'
'TXXX:replaygain_track_gain'                        '+1.08 dB'
'TXXX:replaygain_track_peak'                        '0.789158'

========================== row from database ==========================
                                              'id'  431813
                                            'path'  /data/Music/Bulk/00instruments-classical/Chopin/Romantic Piano Music (Disk 2)/02 Waltz, Grande valse Op. 42 A flat major.mp3
                                         'working'  None
                                         'bitrate'  256
                                    'duration_sec'  237
                                           'genre'  prerock-classical or classical instruments
                                        'filesize'  7617685
                                           'mtime'  1637329781
                                   'redo_metaread'  0
                                        'rest_str'   00instruments classical 02 prerock classical classical instruments
                                      'tag_artist'  Frederic Chopin
                                     'tag_release'  Romantic Piano Music (Disk 2)
                                       'tag_title'  Waltz, Grande valse Op. 42 A flat major
                                             'bpm'  145.1
                                    'search_title'  '42':7 'a':8 'flat':9 'grande':3 'major':10 'op':5,6 'valse':4 'waltz':1,2
                                   'search_artist'  'chopin':2 'frederic':1
                                  'search_release'  '2':6,7 'disk':4,5 'music':3 'piano':2 'romantic':1
                                     'search_rest'  '00instruments':1 'classical':2 'instruments':4 'prerock':3
                                    'search_combo'  '00instruments':20 '2':18C,19C '42':7A 'a':8A 'chopin':12B 'classical':21 'disk':16C,17C 'flat':9A 'frederic':11B 'grande':3A 'instruments':23 'major':10A 'music':15C 'op':5A,6A 'piano':14C 'prerock':22 'romantic':13C 'valse':4A 'waltz':1A,2A
                                    'tag_tracknum'  2
                                      'num_images'  0
                                             'key'  4B
                                           '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-3', 'q-drums-1', 'q-syn-1', 'q-chart-3', 'q-other-1', 'Q-HAP-2', 'Q-PLAY-3', 'q-bass-1', 'q-grit-1']
                                      'lastfmtags'  ['classical', 'piano', 'romantic', 'polish', 'instrumental']
                                        'tag_date'  1993
                                     'discogstags'  []

============================== file details ==============================
                                           'mtime'  1637329780.732752  (2021-11-19 14:49:40)
                             'size'  7617685