432 Librarian: Tag Editor

432 Librarian checks your music library and fixes it: titles, artists, albums, track numbers, cover art and lyrics. You review every change before it is saved, and you can undo it after.

• Fill in missing titles, artists, albums, years and genres from music databases.
• Add cover art and synced lyrics to your own files.
• See which songs your albums are missing, and keep a Wanted list.
• Convert songs to 432 Hz if you prefer how they sound.
• Your songs stay on your device.

The app reads the tags of your songs (MP3, FLAC, M4A, AAC, OGG, Opus, WAV and AIFF) and shows a score and a list of what to fix.

Tools
• Clean up tags: It fixes titles in all capitals or all lower case, extra spaces, featured artists, track numbers repeated in titles and broken characters, and it has find and replace, with regular expressions too.
• Convert: Make copies of songs in another format.
• 432 and 528 files: Make copies of songs tuned to 432 Hz, or to the 528 mode, that play in any player.
• Loudness: Measures how loud each song plays (EBU R128) and writes ReplayGain tags, so players that read them play every song at the same loudness.
• Rename and move: Folders and file names made from the tags.
• Duplicates: The same song more than once, found by its audio.
• Export: Your library or a list as a spreadsheet file (CSV) that Excel, Numbers and Google Sheets open.

Is it free?
Yes, to start. Without an account you can check your whole library and fix 25 songs. A free account fixes 100 songs a month and one whole album a day, and uses the audio tools (convert, 432 Hz files, loudness) 3 times a day. Pro is a single purchase in Google Play and removes every limit.

Does it change my music files?
Only after you review the changes. Fixes are saved into your own files, with a backup copy and Undo. Your songs stay on your device.

What is 432 Hz music?
Music tuned so that the note A is 432 Hz instead of the usual 440 Hz, a little lower. Some people prefer how it sounds. It is a listening preference: 432 Librarian makes no health claims.