StudioToolsAudio metadata
Metadata is information about the audio, stored inside the file: title, artist, credits, comments, technical notes. It travels with the file wherever it goes — if it's stored in the right place and nothing strips it along the way.
Why it matters in the studio
- Credits and rights — artist, engineer and copyright stay with stems and masters when they are sent to mixers, labels or libraries.
- Finding things — sample managers, libraries and search tools index metadata, not just file names.
- Post-production — Broadcast Wave and iXML data tell editors what a clip is and where it belongs on the timeline.
- Delivery — broadcasters and archives often require specific fields, such as a description or loudness values.
Where metadata lives
WAV, AIFF and CAF files are built from chunks. Metadata lives in its own chunks, next to the audio. Each format has its own kinds — and they don't map perfectly onto each other.
WAV
- RIFF
LIST INFO - The original WAV metadata: short text fields identified by four-letter codes —
INAM(title),IART(artist),IPRD(album/product),ICMT(comment),ICOP(copyright),ICRD(creation date),IGNR(genre),IENG(engineer),ISFT(software) and more. Simple and widely supported. bext— Broadcast Wave- Description, originator, date and time, time reference, coding history and loudness. Essential for post and broadcast. Broadcast Wave explained →
iXML- Production sound metadata in XML — scene, take, tape, track names, notes. Written by field recorders.
id3- Some apps embed an ID3 tag (the MP3 tagging format) in WAV files, mainly for music library apps.
cue,LIST adtl,smpl- Markers, regions and loop points — metadata too, even if you don't think of it as text.
AIFF
AIFF has a handful of text chunks: NAME (title), AUTH (author/artist),
(c) (copyright), ANNO (annotation/comment) and COMT (comments with
timestamps). Markers live in MARK, and some apps add an ID3 chunk.
CAF
CAF files have an info chunk: a free list of key–value pairs such as title,
artist, album, composer, tempo, key signature,
recorded date and comments. Flexible, and text is stored as UTF-8, so any language
works.
MP3, M4A and FLAC
Compressed formats have mature tagging systems built for music libraries: ID3 in MP3, MP4 metadata atoms in M4A / AAC / ALAC, and Vorbis comments in FLAC — with artwork, lyrics and much more. They are what Apple Music, Spotify and friends read.
The same field in different formats
| Field | WAV (INFO) | AIFF | CAF info | MP3 (ID3) |
|---|---|---|---|---|
| Title | INAM | NAME | title |
TIT2 |
| Artist | IART | AUTH | artist |
TPE1 |
| Album | IPRD | — | album | TALB |
| Comment | ICMT | ANNO | comments |
COMM |
| Copyright | ICOP | (c) | copyright |
TCOP |
| Genre | IGNR | — | genre | TCON |
When you convert between formats, only fields that exist in both survive — and only if the converter bothers to copy them.
Text encoding
Old formats were designed for plain Western text. RIFF INFO and Broadcast Wave fields are traditionally Latin-1: letters like å, ä, ö, é and ü work, but Greek, Cyrillic, Asian scripts or emoji don't. Some apps write UTF-8 into INFO fields anyway; others then show garbled characters. Broadcast Wave can't store them at all. CAF, ID3 and MP4 tags use Unicode and handle any language.
Who reads what
There is no single standard that every app reads. As a rule of thumb:
| Kind of app | Usually reads |
|---|---|
| DAWs for post-production (e.g. Pro Tools) | Broadcast Wave (time reference, description, originator), often iXML |
| Broadcast and archive systems | Broadcast Wave, including loudness and coding history; sometimes cart |
| Sample managers and audio libraries | RIFF INFO (e.g. IART), Broadcast Wave
description, sometimes iXML or ID3 |
| Music players and streaming uploads | ID3 / MP4 tags on compressed files; WAV support varies |
When delivering files, ask the recipient which fields they need. Filling in both INFO and Broadcast Wave description covers most cases for WAV.
How metadata gets lost
- Converting or re-exporting. Many tools decode the audio and write a fresh file with only format and audio chunks. Everything else — Broadcast Wave, markers, INFO — disappears silently.
- Editing in an audio editor. Some editors rewrite files on save and keep only the chunks they know.
- Changing formats. AIFF can't hold Broadcast Wave data; WAV INFO has no album artist; fields that don't exist in the target format are dropped.
- Upload and delivery platforms that transcode files.
The StudioTools Media Manager works the other way round: it changes only the chunks it needs to and copies every other chunk byte for byte.
Finder tags are not file metadata
The colored tags you add in the Finder look like metadata, but they aren't stored inside the audio file. macOS keeps them alongside the file, in the file system (as an extended attribute). That means:
- They are visible on your Mac, in Finder search and in the Media Manager's Tags column.
- They usually survive copying between Mac drives, but are lost when files are uploaded, emailed, sent through many cloud services, or opened on Windows.
- No DAW or other audio app reads them as part of the audio.
Use Finder tags for your own organization — like marking dual-mono files to deal with later — and embedded metadata for anything that must travel with the file.
Metadata vs. file names
File names are the most robust metadata of all: every system shows them and nothing strips them. Good practice is
to use both — a clear, consistent file name (SongA_VoxLead_Take3.wav) and embedded fields for
everything that doesn't fit in a name.