Qtractor – audio/MIDI multi-track sequencer software

Qtractor is an Audio/MIDI multi-track sequencer application written in C++ around the Qt4 toolkit.

The Jack Audio Connection Kit (JACK) for audio, and the Advanced LinuxSound Architecture (ALSA) for MIDI, are the main infrastructures to evolve as a fairly-featured Linux Desktop Audio Workstation GUI, especially dedicated to the personal home-studio.

Qtractor is a non­destructive sequencer and arranger. It does not affect, alter or modify in any way, the audio and/or MIDI files that are displayed as Clip Objects. What is destructive are files resulting from capture and recording operations, and explicit changes made through specialized Clip editing (e.g., MIDI Editor).

Qtractor is a fairly massive multi­threaded application. For instance, each audio clip has a dedicated disk I/O executive thread, which synchronizes with the master engine and, for all purposes, to central JACK real­time audio processing cycle, through a lock­free ring­buffer.

Features include:

  • Multi-track audio and MIDI sequencing and recording.
  • Supports all sample rates only restricted by hardware.
  • Supports multiple audio file formats, both compressed and uncompressed, including older formats such as 8SVX and .iff.
  • Clip editing and automatic or manual Time Stretching abilities.
  • Supports most major audio and MIDI file formats and most Linux plugin technologies.
  • Clips, may be easily edited by simply dragging the left or right edges for cropping, or even for timeshifting, by using the shift key modifier.
  • Use in an audio mastering environment. Its integration with JACK makes it possible to use mastering tools such as JAMin to process the audio data.
  • Both an audio and MIDI metronome with user selectable audio samples.
  • Easily move and copy plugins (with params) among tracks.
  • Keyboard commands (hotkeys) are entirely customizable.
  • Audition audio files within the Files dialog.
  • Built-in Qjackctl Connections dialog.
  • Support for Cakewalk instrument definition files.
  • MIDI editor.
  • Audio / MIDI export.
  • Audio file formats support: OGG, MP3 (via libmad, playback only), WAV, FLAC, AIFF and many more.
  • LADSPA, DSSI, native VST and LV2 plug-ins support.
  • DSSI and Native VST Plugin Support.
  • Snap/Zoom Menu Accessibility.
  • OSC or D-BUS interface.
  • Unlimited undo/redo.
  • Configurable keyboard shortcuts.

Website: qtractor.org
Support: GitHub Code Repository
Developer: Rui Nuno Capela
License: GNU GPL v2


Qtractor is written in C++. Learn C++ with our recommended free books and free tutorials.

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