What Audio File Formats Are Used in Music Distribution?

Modern music production relies on a specific ecosystem of digital audio formats divided into uncompressed master files, compressed lossless alternatives, and efficient lossy codecs for streaming and downloads. When delivering final masters to digital service providers (DSPs) such as Spotify, Apple Music, and Amazon Music, distributors require high-resolution source files to transcode consumer-ready versions. Understanding the roles of WAV, FLAC, AAC, MP3, and emerging spatial audio standards ensures tracks preserve fidelity across all playback environments.

Uncompressed Formats for Master Delivery

WAV (Waveform Audio File Format)

WAV is the universal industry standard for delivering masters to digital distributors and record labels. Using uncompressed Linear Pulse-Code Modulation (LPCM), WAV files retain every dynamic detail and frequency nuance captured during the recording and mastering stages without data loss.

• Standard Delivery Specs: 24-bit or 16-bit depth at 44.1 kHz, 48 kHz, or 96 kHz sample rates.
• Primary Role: Archival, streaming aggregator ingest, physical CD authoring.

AIFF (Audio Interchange File Format)

Developed by Apple, AIFF functions identically to WAV in terms of raw audio quality and uncompressed PCM storage. While accepted by many major distributors, WAV remains more universally supported across non-Apple toolchains.

Lossless Compressed Formats

Lossless formats reduce file sizes by 30% to 60% compared to raw WAV files while restoring bit-for-bit identical audio upon decoding.

FLAC (Free Lossless Audio Codec)

FLAC is the leading open-source lossless format. Widely used by direct-to-fan distribution platforms like Bandcamp, audiophile streaming tiers (such as Tidal HiFi), and online music stores, FLAC provides high fidelity alongside robust metadata tagging capabilities.

ALAC (Apple Lossless Audio Codec)

ALAC serves as Apple’s proprietary equivalent to FLAC. It underpins Apple Music’s lossless and high-resolution lossless streaming catalogue, delivering audio resolutions up to 24-bit/192 kHz within the Apple hardware and software ecosystem.

Lossy Consumer Formats

To ensure smooth streaming over cellular networks and save bandwidth, platforms convert lossless masters into lossy formats that remove frequencies beyond typical human hearing thresholds.

AAC (Advanced Audio Coding)

AAC is the modern successor to MP3, providing superior frequency reproduction and clarity at comparable or lower bitrates. It is the standard playback format for Apple Music (typically 256 kbps) and YouTube Music.

Ogg Vorbis

Ogg Vorbis is an open-source lossy codec used extensively by Spotify for its standard web and mobile streaming tiers, scalable up to 320 kbps for Premium subscribers.

MP3 (MPEG-1 Audio Layer III)

Though largely replaced by AAC and Ogg Vorbis on modern streaming servers, MP3 (specifically 320 kbps CBR) remains widely distributed for digital downloads, promotional DJ pools, syncing libraries, and consumer playback compatibility.

Spatial and Immersive Audio Formats

Modern distribution channels increasingly support immersive formats alongside stereo audio:

• Dolby Atmos (ADM BWF): Producers deliver multi-channel immersive mixes as specialized Broadcast Wave Files containing bed audio and spatial object metadata. Platforms transcode these into spatial formats like Dolby Digital Plus with Atmos for consumer playback on headphones and multi-speaker setups.
• Sony 360 Reality Audio: Based on the open MPEG-H 3D Audio standard, this format maps audio objects in a full spherical field for supported streaming services.