Path Formats

The paths: section of the config file (see Configuration) lets you specify the directory and file naming scheme for your music library. Templates substitute symbols like $title (any field value prefixed by $) with the appropriate value from the track’s metadata. Beets adds the filename extension automatically.

For example, consider this path format string: $albumartist/$album/$track $title

Here are some paths this format will generate:

  • Yeah Yeah Yeahs/It's Blitz!/01 Zero.mp3
  • Spank Rock/YoYoYoYoYo/11 Competition.mp3
  • The Magnetic Fields/Realism/01 You Must Be Out of Your Mind.mp3

Because $ is used to delineate a field reference, you can use $$ to emit a dollars sign. As with Python template strings, ${title} is equivalent to $title; you can use this if you need to separate a field name from the text that follows it.

A Note About Artists

Note that in path formats, you almost certainly want to use $albumartist and not $artist. The latter refers to the “track artist” when it is present, which means that albums that have tracks from different artists on them (like Stop Making Sense, for example) will be placed into different folders! Continuing with the Stop Making Sense example, you’ll end up with most of the tracks in a “Talking Heads” directory and one in a “Tom Tom Club” directory. You probably don’t want that! So use $albumartist.

As a convenience, however, beets allows $albumartist to fall back to the value for $artist and vice-versa if one tag is present but the other is not.

Template Functions

Beets path formats also support function calls, which can be used to transform text and perform logical manipulations. The syntax for function calls is like this: %func{arg,arg}. For example, the upper function makes its argument upper-case, so %upper{beets rocks} will be replaced with BEETS ROCKS. You can, of course, nest function calls and place variable references in function arguments, so %upper{$artist} becomes the upper-case version of the track’s artists.

These functions are built in to beets:

  • %lower{text}: Convert text to lowercase.
  • %upper{text}: Convert text to UPPERCASE.
  • %title{text}: Convert text to Title Case.
  • %left{text,n}: Return the first n characters of text.
  • %right{text,n}: Return the last n characters of text.
  • %if{condition,text} or %if{condition,truetext,falsetext}: If condition is nonempty (or nonzero, if it’s a number), then returns the second argument. Otherwise, returns the third argument if specified (or nothing if falsetext is left off).
  • %asciify{text}: Convert non-ASCII characters to their ASCII equivalents. For example, “café” becomes “cafe”. Uses the mapping provided by the unidecode module. See the asciify_paths configuration option.
  • %aunique{identifiers,disambiguators}: Provides a unique string to disambiguate similar albums in the database. See Album Disambiguation, below.
  • %time{date_time,format}: Return the date and time in any format accepted by strftime. For example, to get the year some music was added to your library, use %time{$added,%Y}.

Plugins can extend beets with more template functions (see Template functions and values provided by plugins).

Album Disambiguation

Occasionally, bands release two albums with the same name (c.f. Crystal Castles, Weezer, and any situation where a single has the same name as an album or EP). Beets ships with special support, in the form of the %aunique{} template function, to avoid placing two identically-named albums in the same directory on disk.

The aunique function detects situations where two albums have some identical fields and emits text from additional fields to disambiguate the albums. For example, if you have both Crystal Castles albums in your library, %aunique{} will expand to “[2008]” for one album and “[2010]” for the other. The function detects that you have two albums with the same artist and title but that they have different release years.

For full flexibility, the %aunique function takes two arguments, each of which are whitespace-separated lists of album field names: a set of identifiers and a set of disambiguators. Any group of albums with identical values for all the identifiers will be considered “duplicates”. Then, the function tries each disambiguator field, looking for one that distinguishes each of the duplicate albums from each other. The first such field is used as the result for %aunique. If no field suffices, an arbitrary number is used to distinguish the two albums.

The default identifiers are albumartist album and the default disambiguators are albumtype year label catalognum albumdisambig. So you can get reasonable disambiguation behavior if you just use %aunique{} with no parameters in your path forms (as in the default path formats), but you can customize the disambiguation if, for example, you include the year by default in path formats.

One caveat: When you import an album that is named identically to one already in your library, the first album—the one already in your library— will not consider itself a duplicate at import time. This means that %aunique{} will expand to nothing for this album and no disambiguation string will be used at its import time. Only the second album will receive a disambiguation string. If you want to add the disambiguation string to both albums, just run beet move (possibly restricted by a query) to update the paths for the albums.

Syntax Details

The characters $, %, {, }, and , are “special” in the path template syntax. This means that, for example, if you want a % character to appear in your paths, you’ll need to be careful that you don’t accidentally write a function call. To escape any of these characters (except {), prefix it with a $. For example, $$ becomes $; $% becomes %, etc. The only exception is ${, which is ambiguous with the variable reference syntax (like ${title}). To insert a { alone, it’s always sufficient to just type {.

If a value or function is undefined, the syntax is simply left unreplaced. For example, if you write $foo in a path template, this will yield $foo in the resulting paths because “foo” is not a valid field name. The same is true of syntax errors like unclosed {} pairs; if you ever see template syntax constructs leaking into your paths, check your template for errors.

If an error occurs in the Python code that implements a function, the function call will be expanded to a string that describes the exception so you can debug your template. For example, the second parameter to %left must be an integer; if you write %left{foo,bar}, this will be expanded to something like <ValueError: invalid literal for int()>.

Available Values

Here’s a list of the different values available to path formats. The current list can be found definitively by running the command beet fields. Note that plugins can add new (or replace existing) template values (see Template functions and values provided by plugins).

Ordinary metadata:

  • title
  • artist
  • artist_sort: The “sort name” of the track artist (e.g., “Beatles, The” or “White, Jack”).
  • artist_credit: The track-specific artist credit name, which may be a variation of the artist’s “canonical” name.
  • album
  • albumartist: The artist for the entire album, which may be different from the artists for the individual tracks.
  • albumartist_sort
  • albumartist_credit
  • genre
  • composer
  • grouping
  • year, month, day: The release date of the specific release.
  • original_year, original_month, original_day: The release date of the original version of the album.
  • track
  • tracktotal
  • disc
  • disctotal
  • lyrics
  • comments
  • bpm
  • comp: Compilation flag.
  • albumtype: The MusicBrainz album type; the MusicBrainz wiki has a list of type names.
  • label
  • asin
  • catalognum
  • script
  • language
  • country
  • albumstatus
  • media
  • albumdisambig
  • disctitle
  • encoder

Audio information:

  • length (in seconds)
  • bitrate (in kilobits per second, with units: e.g., “192kbps”)
  • format (e.g., “MP3” or “FLAC”)
  • channels
  • bitdepth (only available for some formats)
  • samplerate (in kilohertz, with units: e.g., “48kHz”)

MusicBrainz and fingerprint information:

  • mb_trackid
  • mb_albumid
  • mb_artistid
  • mb_albumartistid
  • mb_releasegroupid
  • acoustid_fingerprint
  • acoustid_id

Library metadata:

  • mtime: The modification time of the audio file.
  • added: The date and time that the music was added to your library.
  • path: The item’s filename.

Template functions and values provided by plugins

Beets plugins can provide additional fields and functions to templates. See the Plugins page for a full list of plugins. Some plugin-provided constructs include:

  • $missing by Missing Plugin: The number of missing tracks per album.
  • %bucket{text} by Bucket Plugin: Substitute a string by the range it belongs to.
  • %the{text} by The Plugin: Moves English articles to ends of strings.

The Inline Plugin lets you define template fields in your beets configuration file using Python snippets. And for more advanced processing, you can go all-in and write a dedicated plugin to register your own fields and functions (see Writing Plugins).