.ALS

Ableton Live Set

Introduction

An Ableton Live Set is a project saved by Ableton Live. It holds the tracks, clips, arrangement, devices, mixer settings and automation of a song. Audio samples are not stored inside it: the set refers to sample files on disk, usually kept beside it in a Live project folder.

The file is XML compressed with gzip, so it can be unpacked and read as text. Its elements follow Live’s own internal model, which changes between Live versions and is not published as a specification.

Software

Structure

On disk the file is a gzip stream, starting with the bytes 1F 8B. Unpacked, it is an XML document whose root element is Ableton, with attributes naming the version of Live that saved it. Inside is a LiveSet element holding the tracks (audio, MIDI, return and group tracks), the master track, the scenes, the locators and the transport settings. Each track holds its clips, device chain and mixer, and clips refer to sample files by path.

  1. 0gzip header 1F 8B, method, flags, time10 bytes
  2. 10Compressed XML the Ableton documentvaries
    1. Ableton root element, version attributes
    2. LiveSet tracks, master track, scenes, locators, transport
  3. endgzip trailer CRC-32 and size of the XML8 bytes
An Ableton Live Set: gzip around an XML document.