How are Albums and Artists defined in the Library (using 'tags' within audio files)

Tags / Metadata

Metadata is extra information about a song, stored as hidden computer-readable data within an audio file. This is independent of the filename or folder location - the data is stored inside the file as individual embedded 'tags'. Some tags are technical specs such as encoding methods and duration, while others contain things like the Title of each song or are used organise your music into various categories for easier viewing and access - such as Albums, Artists, Genres, Years, etc.

Some commonly used tags are:

  • Song Title [TIT2 / TITLE]
  • Artist [TPE1 / ARTIST]
  • Album Title [TALB / ALBUM]
  • Album Artist [TPE2 / ALBUMARTIST, or sometimes ALBUM ARTIST]
  • Genre [TCON / GENRE]
  • Track Number [TRCK / TRACKNUMBER]
  • Disc Number for multi-disc sets [TPOS / DISCNUMBER]
  • Year [TYER / DATE]
  • Composer [TCOM / COMPOSER]
  • Lyrics [USLT / LYRICS]
  • Synchronised Lyrics [ SYLT / - ] Note: rarely used, timecoded lyrics are often encoded within the regular Lyrics tag
  • Comment (not used by Poweramp, but can be displayed) [COMM / COMMENT]
  • Length (ms) [TLEN]
  • Replay Gain [TXXX:REPLAYGAIN_**** / REPLAYGAIN_****]
  • Album Cover (image) [APIC / METADATA_BLOCK_PICTURE]

You can view any tags contained within a song file by long-pressing on the song title in a library list, or long-pressing on the cover artwork in the player screen, and selecting 'Info/Tags'. You can also edit some tags by then tapping 'Edit Tags'. For more in-depth editing, or changing groups of file contents at the same time, it would be better to utilise a full-featured batch tagging program such as TagScanner or MP3Tag on a PC, or AutoTagger on Android.

Technical note: MP3 files usually use the ID3 tagging format (see https://en.wikipedia.org/wiki/ID3) while FLAC files use the Vorbis system (see https://www.xiph.org/vorbis/doc/v-comment.html). Both methods contain broadly the same information but encoded slightly differently, as annotated above - and in more detail in https://wiki.hydrogenaud.io/index.php?title=Tag_Mapping. APE is another, slightly less common, tagging method. Poweramp can read and use any of these tagging systems. Completely untagged files, or files where for some reason the tags cannot be read by the scanner, will be displayed using their filenames only, and you will need to organise them by their folder locations.


What tags are needed to group a number of songs into one 'Album'

An 'album' is merely a notional grouping of any songs within the Library that have the exact same Album and Album Artist tags - but which may still have different Artist tags.

Should Album Artist tags be missing, Poweramp will fall back to trying to group songs into albums based on the Album and Artist tags instead - but often with mixed levels of success, as Artist names can vary track-by-track - such as featured artists, duets, compilations, etc. In these cases, it is vital that Album Artist tags are correctly assigned, using a common term such as "Various Artists", to ensure all the songs remain together. It's actually a good idea to always include an Album Artist tag anyway, even if the content happens to be the same as the track Artist.Poweramp will try to infer some other properties for an 'album' - such as the Year and Genre - but these concepts are based solely on looking at the constituent songs and picking a value from them. If those tags are not consistent throughout - e.g. if each track in a compilation album has a different Year value - then the overall value chosen may not be predictable.
 

Multiple instances of one tag type - e.g. several Artists for one song 

From build 899 onward, Poweramp can separate and sort songs using multiple names - e.g. "Under Pressure" could be listed as being by "David Bowie ; Queen" and it would be shown in the Artist listing for David Bowie and also for Queen. This feature can be used for Artists, Album Artists, Composers, and Genres (e.g. a genre could be listed as "New Wave ; Electronic ; New Romantic"). You can even define your own symbols or words to be used as separators via PA Settings > Library > Scanner, but semicolon ";" , slash "/" or double-slash "//" are common ones. It's a good idea to avoid using commas or ampersands though, because of band names like "Earth, Wind & Fire", "Emerson, Lake & Palmer", etc. You can also specify certain phrases that you never want to be split - e.g. "AC/DC". If you don't wish to use this feature, simply leave the relevant options blank.

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