Qtractor is a multi-track Audio and MIDI recorder and editor. The program is written in C++, and for the GUI (graphical user interface) elements, the Qt4 Toolkit and Qt Designer are used. Qtractor is free open-source software, licensed under the GPL, and the project welcomes all collaboration and review from the Linux audio developer and user community in particular, and the public in general.
Currently the Qtractor project has one developer, the originator of the project, Rui Nuno Capela. Development was started April of 2005, initially as a Qt3 application. Since October 2006, it is officially a Qt4
The initial target OS platform is Linux, in which ALSA (Advanced Linux Sound Architecture
) and JACK (the Jack Audio Connection Kit
) form the supporting infrastructure for recognizing sources of digital audio and MIDI (musical instrument digital interface) data, communicating with those sources and routing the data to and from various locations and programs (applications, including Qtractor) both inside and outside the computer and involving both software and hardware interfaces.
The goal is to develop Qtractor into a more and more full-featured and robust digital audio/MIDI workstation, especially appropriate for personal home recording studio use.
Illustration 1.1: Main GUI window showing audio & MIDI tracks, Mixer & Connections windows
Although Qtractor will become more and more full-featured as it is developed, it can already be comfortably used by hobbyists as a personal home recording studio or "bedroom studio." It can record, import, arrange and edit both digital audio and MIDI data. The functionality of Qtractor is contained within a graphical desktop environment that will be familiar to users of other popular multi-track recording/editing applications on any computer operating system, and follows the same design principles with many of the same or similar elements. In addition to recording digital audio and MIDI, Qtractor provides an environment for multi-track clip-oriented composing techniques common in modern music-making and aims to be intuitive and easy to use, yet powerful enough for the serious recording enthusiast.
Note: Qtractor is not what is known as a "tracker" type of audio/MIDI application, although it has the potential to function in that way if needed.
When used merely as an audio and/or MIDI recorder (a MIDI recorder was historically called a "sequencer") or arranger, Qtractor is non-destructive, which means that the underlying files that contain the audio or MIDI data are not altered when those files are apparently cut into pieces, duplicated, pulled or pasted into a different order in time, or manipulated in any number of ways within the main Window (GUI interface) of Qtractor. However, when used as an audio or MIDI recorder, for example, or when editing previously recorded MIDI data in the dedicated MIDI editor, Qtractor's actions can be destructive in the sense that newly recorded data (or altered MIDI data) replaces previously recorded data on the same track.