Master Formats and Metadata: A Comprehensive Guide for Music Distribution

Table of Contents

Masters Formats for distribution

The final file formats of your final masters will vary depending on the medium you are releasing your music on. It good practice to lets your mastering engineer know in advance what formats are you releasing your music so they can prepare all the final deliverables accordingly.

Format required: 16bit 44.1Khz WAV files

Common aggregators suggested by Apple Music and Spotify are:
CD BabyTuneCoreDistroKidEmubandsAWALThe OrchardRecord UnionSoundropRoutenoteBandcamp, etc.

With most aggregators, you can distribute your music via iTunes StoreAmazon MusicGoogle PlaySpotifyTIDALDeezer, etc.

Mastered For iTunes: 24bit 96khz WAV files
Most of the above aggregators and streaming platforms are already accepting MFiT files but you might need to check with your online distributor/aggregator for specific details.

Bandcamp and SoundCloud: 24bit WAV files (sample rates above 44.1k)

Format Required: DDP image or 16bit 44.1khz WAV files

A DDP image is basically a digital image of a compact disc that contains all the audio, track IDs, CD-Text, and ISRC codes.

DDP is not prone to errors that can occur with physical CDs (and CD-Rs) such as skips, scratches, and read/write errors. This is in part why it’s best to use a DDP image for your CD production master rather than a physical CD-R.

It is not recommended to submit individual WAV files for CD production. This can lead to problems with song sequencing, incorrect CD-Text, lack of CD-Text, and in some cases the audio itself can be altered if files are handled improperly.

Learn more about the DDP file format here.

The WAV files for your vinyl pre-master can be at the native sample rate of your original mixes and/or mastering session (meaning higher than 44.1k/CD quality).

Creating a single WAV for each side of the record will ensure that no changes with the space and timing between songs can occur at the lacquer cutting stage.

Sonic adjustments are often made to optimize for the vinyl format before sending it off the pressing plant or lacquer cutter. Some of the things to address during the mastering session include:

  • Ensure bass is not overly pronounced below 40Hz.
  • Reduce excessive sibilance and high-frequency content such as cymbals, hi-hats, and shakers.
  • Control the dynamics without excessive levels or distortion.

Format Required: 16bit WAV files (sample rates higher than 44.1k in some cases)

Most cassette manufacturers usually ask for 16-bit/44.1k audio though some boutique manufactures may be able to work with higher resolution audio files.

Creating a single WAV for each side of the cassette (or “program”) will help ensure that no changes with the space and timing between songs can occur. You may wish to optimize audio for the cassette format, as it may not need to be as loud and compressed, and sibilance can be an issue with certain types of tape. Check with the manufacturer for their specs.

Format Required: 48khz WAV files (with 320kbps reference mp3)

The proper format needed for licensing your music will ultimately depend on who licenses the music, and how you plan to distribute it. However, the most common audio format for video use is 48k WAV, though 24-bit/96k is becoming more common for Blu-Ray releases.

Masters Metadata options for distribution

Metadata is the details/information that the mastering engineer will embed on your final masters. Is good practice to provide this information to the mastering engineer before all final deliverables are prepared and sent out.

WAV & AIFF files don’t support the large amount of metadata that an mp3 or AAC file can contain. If you are uploading WAV files to online distribution services, expect to submit the artwork and other metadata separately as you submit the audio files for online distribution. The distribution service you use will handle the metadata tagging that is seen by the end user based on the info you enter, and what is supported by the end file format.