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MP3 Metadata: ID3 Tag and Filename Best Practice
Tue, 05/04/2004 - 19:58
All digital media needs extensive embedded information (metadata). From the consumer's viewpoint, media is much more useful when it contains rich information about the work. From an artist's perspective, digital media delivered via the web can only offer promotional benefit to the owner if it contains proper credits. This "Best Practice" report assumes that you already know the importance of extensive metadata, and will just describe my proven methods of implementation.
[MP3 audio encoding methodology (MP3LAME vs AAC vs WMA etc.) is a separate discussion. The encoding short story: future-proof your audio by creating original masters in an uncompressed file format. Today's standard uncompressed audio format is Broadcast WAV. Broadcast WAV files (abbreviated BWF) have the file extension .wav, just as WAVE files do, but Broadcast WAV files contain additional metadata. However it is important to note that .wav files do NOT hold the type of metadata that applications such as iTunes read and write, namely ID3 tags. AIFF files do hold ID3 tags. Portable compressed formats (MP3, AAC etc.) will inevitably change, so each time return to the original master and create a new compressed file. Pick the highest bitrate available. Unfortunately, a remaining challenge is migrating ID3 tag data from the previous compressed format each time a new reformatting is necessary.]
I have written this to share my findings and methods with others like myself who manage large collections of music. This will help your music library maintenance by creating a consistent metadata and filename structure.
These methods apply for any file format which can be tagged with metadata (MP3, AAC, AIFF etc). Example methods are platform-independent except a few OS X apps; the reasoning and results are universal. All of this might seem picky to you unless you manage dozens of gigabytes of files or distribute music online. Eventually this will become essential for any collection as it grows, so learn now or live with a mess later.
For today's popular compressed audio formats such as MP3 and AAC, each track's info is kept in ID3 tags. Complete tags enable powerful manipulations such as automated playlists, click-to-buy links and multiple-field sorting. Info in filenames is much less useful and should contain no more than the Artist and Title to reduce clutter. (To be precise, AAC files don't technically use ID3 tags- they use a different standard with the same field names as ID3 so the rules below all still apply. Windows Media files have metadata tags as well... sort of.)
There are numerous revisions to the ID3 tag specification, but the best version presently is ID3 v2.3. (There's also v2.4 but it is not yet compatible with all player apps.) ID3 v2 was a complete revamp over v1, adding new fields such as bpm, composer, music-synced lyrics for karaoke, and it allows for future expansion fields. ID3 v1 tags could not hold much data (<30 characters) and had few fields. Here's a nice explanation and more:
More on the ID3 spec and the differences between versions:
One more note and I'll wrap up this long intro. If you can't do all of what I'm recommending, at least create complete metadata (ID3 tags). If you don't follow my recommendations for the filename, you'll be fine. But at least complete the metadata!
My process for new MP3 files:
First, if you're using iTunes (PC or Mac), I DON'T want iTunes renaming files with just the track name (no artist), so make sure to uncheck this preference:
Advanced --> General --> "Keep iTunes Music Folder Organized"
Also, uncheck Advanced --> Importing --> "Create file names with track number"
Batch-convert all ID3 tags to v2.3 with iTunes:
(iTunes-->Advanced menu-->Convert ID3 Tags, or just right-click on the songs).
iTunes (version 4) sets ID3 v2.2 tags by default when ripping. That's usually fine, but I go for v2.3. I don't recommend v2.4 until more players recognize it. But if you just use iTunes or another app that can read v2.4, then v2.4 is fine.
Fix info in the tags which is inevitably lacking even if from a built-in feature such as iTunes "Get track names" (this pulls data from Gracenote, which comes from end-user submissions). The best second-opinion for info is allmusic.com, aka the All Music Guide aka AMG. I have written custom scripts to lookup a track's artist/title/album on allmusic.com. iTunes 4.5 adds buttons to the top 3 fields to check it at the iTMS.
The genre tag is extremely important to my system. Each track is individually assigned one of my own 46+ custom alphabetically-arranged genres. When adding an album to my collection, I only add the keeper tracks, and treat each keeper individually. (Don't get me started about hiphop "interlude" skits!) This is much more useful than assigning the same genre to an entire album and avoids the dreaded moodkiller shuffle track:
For multi-artist compilations and "best of"s, I like to research the original album release of each track, after double-checking that it is the same original version (check the track length). At the very least, I correct the year.
Other ID3 tag entry rules:
- Guest stars' names do not go in the song title. Add them to the Artist field for that song after the word "featuring" (which is not capitalized).
- Do not include multi-disc set "[Disc #]" in the album title. That goes in the "disc _ of _" fields.
- If possible, include year, composer, etc.
- I use the comments section for web URLs, sample spotting, mix ideas, keywords, mashup sources etc. Don't waste the comments field with the name of the encoding app (it's already in the "encoded with" field).
- Make sure your application is writing the info into the mp3 file itself, and not just entering it into a proprietary database that references the file. For example, there are a few items which iTunes doesn't put in the file, such as the rating and the volume. These get stored in the separate iTunes (XML) Music Library.
- The "grouping" field can be used for classical movements or compilation source when the original album is known.
- Replace ampersands ("&") with the word "and". (The ampersand is displayed weirdly by some web-based playlists because it is interpreted as HTML code.)
[edit 2007: watch out for iTunes version 7's Album Art handling. If you use the "Get Album Artwork" function, iTunes doesn't put the art in the file itself.]
Album art is retrieved (from Amazon or Google) and copied into the files with iTunes or an app such as:
Run a script which renames filenames in this format:
[Those applescripts may require changing settings such as one which replaces illegal characters with _'"’!?#(),+&.* /: ]
For further filename manipulation, try this handy utility, which can even read the ID3 tags and name the file as you wish,
for PC it's called A Better File Rename:
for Mac it's called A Better Finder Rename:
That app is priceless! I've built stand-alone applets that do all kinds of renaming batch work.
Run a script which moves the files into genre folders. Most normal humans use ArtistName folders, but I like genres because it makes backups, burning MP3 CDs and playlist-building easier. Download my script here (Mac Only, the instructions are in the script code - open with Script Editor):
•))) (optional. Actually, most of this is optional for everyone but me. sigh.)
Finally, all tracks are imported into Traktor DJ Studio for beats-per-minute and waveform analysis:
Traktor DJ Studio
Once they are ripped, the CDs go in storage. I put a little sticker on the back of each ripped CD case so I can tell if/how it's been ripped. I list three things on that sticker: the bitrate, the date and the number of tracks ripped. This will come in handy in the future when I inevitably need to rerip.
Periodically review collection for missing info by sorting each field, or by smart playlists programmed to return empty fields.
Still unresolved: If an album is a "greatest hits" with all songs by one artist, is it technically a "compilation"? I like to enter the original year of release for each track and when available, the original album title. But when I don't do that, I tag these albums as "compilations."
However, some applications (in particular iTunes) don't think that way when sorting a library of songs. They consider this to NOT be a compilation, because the artist of each track is the same.
So I'm considering changing my stance on greatest hits compilations.
I'm open to suggestions, and I welcome feedback, particularly on PC apps to augment those listed above.
I'll post more on this as I go. Hope that helps!
p.s. I'm more than just an insanely obsessive music librarian. I make good use of this for DJ gigs:
[ This article was updated a few times in 2004 and 2005. ]
Mon, 07/12/2004 - 15:45#1
I was wondering if you could tell me abit more about META DATA and its involvement in MP3 ENCODING in relation to putting out material on ITunes and Napster. I've been referred to Association of Independant Music. I'm after software that allows this process.
Mon, 07/12/2004 - 16:53#3
Thanks for your reply, wou;d it possible to refer me to some programs by professional bodies that allow ID tags to be inserted, as the information inserted into iTunes really isn;t enough. For example, Composer, Lyrics, and IRc code of the album.
Also from iTunes do you know how to import the music from the Library onto iTunes website for people to buy?
Tue, 07/13/2004 - 18:04#5
Hi, thanks for your help, but I've this query raised by my senior that these don’t allow you to customise the metadata you enter on the MP3 as we need it.
Hence, a programme that can read metadata off an Excel or Csv file ...
Sun, 02/11/2007 - 19:36#6
I hope you aren't a psycho because I have to tell you: I adore you.
I was hoping you could clarify a few things for mei. I am a PC user:
1. I am still a little confused about the difference between and ID3 tag and a Windows Media files metadata tags. Are you using the two terms synonymously? I read the http://msdn.microsoft.com/en-us/library/ms867702.aspx article you cited, but it isn't helping much. I assume the Windows Media files metadata tag is when you right-click on an MP3 file > Properties > Summary tab > Advanced button. Is this correct?
2. Why can't I add an entire song's worth of lyrics in the lyric field here? I get an error pop-up, titled "Summary Properties" that reads "a disk error occured during write operation." Strangely, however, if I divide the lyrics into two parts, then cut and copy the two parts separately, it works! Is there some sort of character max. limit that I can add to the lyric field at one time? I thought that maybe there's some hidden formatting info. that I copied that the metadata didn't like, so I copied and pasted all of the lyrics to Notepad (which I know is neutral) and then tried to copy and paste from there into the Lyrics field in the metadata, but that didn't work either. The only way I could successfully add lyrics was to divide by two. But that's double the work!
3. What is the best way to retrieve and input lyric info. into my metadata (or is it "ID3"?)?
4. Is there a source you know of that already includes lyrics in the metadata so I don't have to put it in manually myself? Do some artists have this info. pre-programmed on their songs/albums now?
5. Do you know how the WM/Lyrics_Synchronised feature works in Windows? It is really confusing. It mentions this feature in the article (above link), but it didn't help me.
6. Since I could not add lyrics (easily) into the metadata of my MP3s, I got coerced into using iTunes' "Get Info" feature (right-click > Get Info). I could easily add lyrics in their lyrics tab there. You warned: "Make sure your application is writing the info into the mp3 file itself, and not just entering it into a proprietary database that references the file. For example, there are a few items which iTunes doesn't put in the file, such as the rating and the volume. These get stored in the separate iTunes (XML) Music Library." Do you strongly recommend against this? I would rather store my lyrics in the metadata of each MP3 file, but like I said, it hasn't been working smoothly for me.
7. iTunes question: What is the best way to back up your files? How is the File > Export feature different from the File > Backup onto DVD or CD-R feature? And how are those different from manually copying the entire iTunes parent folder?
8. iTunes question: When I copy/back-up my iTunes Library, will it backup my Lyrics if it is stored in the "Get Info" area?
9. iTunes question: In the "Get Info" area, the Artist and Album Name populate. Did this info. come from the MP3 file's metadata/ID3 tag?
10. What about album artwork? What's the best way to put it into my metadata/ID3 tag? Will it populate in the "Get Info" area if I have it stored in the MP3 file's metadata/ID3 tag? Same with lyrics? If I can successfully add lyrics to the metadata of the MP3 (ie. not the Get Info feature in iTunes as I'm reluctantly doing it now), will it auto-populate in the lyrics tab in the Get Info area of iTunes?
11. Last question: change of subject: I am old fashioned. I buy the CD, RIP it, then transfer the music into my iTunes. Is it best to RIP it as an MP3 file?
Feel free to elaborate! I am going to go read the rest of your posts now. Thank you so much for your help!
Sun, 02/11/2007 - 19:49#7
Nkee's question #1: Okay, I get it now. I just read your "Mon Jul 12, 2004 5:40 pm" post.
Sun, 02/11/2007 - 19:59#8
Sat, 02/24/2007 - 15:26#10
I just came across a new problem: I was trying to run our little test, but I couldn't locate the original file in my iTunes music folder (and therefore, couldn't check whether or not the lyrics would be saved into the metadata of the file that's associated with the song that appears in iTunes Library, when I add lyrics into the "Get Info" section there.) Is this because the box "Copy music to iTunes music folder when adding to library" box is NOT checked? Originally, I just dragged and dropped my MP3 files from their original location right into the iTunes Library interface. Does that mean that the files still in their original spots b/c I didn't check the box? And does that imply that all information added into the "Get Info" screen in iTunes Library will not get saved into the metadata of the song because there isn't even an actual file associated with it? It's definitley not associated with the original file that I dragged and dropped into iTunes Libaray; I'm sure because it's not taking the lyric info that I pasted into "Get Info," which - according to our experiment - it should have.
Tue, 02/27/2007 - 07:38#11
In the 1st post on this topic you wrote "I have written custom scripts to lookup a track's artist/title/album on allmusic.com". Is it possible that you could make these scripts available?
what I need is a source to which I can submit the SongName-Artist and it provides me Genre AND Sub-Genre (style in the case of AMG) along with other information about the song.
Your help would be appreciated.