Some words about DAW
A digital audio workstation (DAW) is an electronic system designed solely or primarily for recording, editing and playing back digital audio. DAWs were originally tape-less, microprocessor-based systems such as the Synclavier and Fairlight CMI. Modern DAWs are software running on computers with audio interface hardware.
An integrated DAW consists of a mixing console, control surface, audio converter, and data storage in one device. Integrated DAWs were more popular before personal computers became powerful enough to run DAW software. As computer power increased and price decreased, the popularity of the costly integrated systems with console automation dropped. Systems such as the Orban Audicy once flourished at radio stations and television station. Today, some systems still offer computer-less arranging and recording features with a full graphical user interface (GUI).
A computer-based DAW has four basic components: a computer, a sound converter (also called a sound card or audio interface), a digital audio editor software, and at least one input device for adding or modifying musical note data. This could be as simple as a mouse, and as sophisticated as a MIDI controller keyboard, or an automated fader board for mixing track volumes. The computer acts as a host for the sound card and software and provides processing power for audio editing. The sound card (if used) or external audio interface typically converts analog audio signals into digital form, and for playback converting digital to analog audio; it may also assist in further processing the audio. The software controls all related hardware components and provides a user interface to allow for recording, editing, and playback. Most computer-based DAWs have extensive MIDI recording, editing, and playback capabilities, and some even have minor video-related features. Simple smartphone-based DAWs, called Mobile Audio Workstation (MAWs), are also available, used for example by journalists for recording and editing on location.
As software systems, DAWs could be designed with any user interface, but generally they are based on a multitrack tape recorder metaphor, making it easier for recording engineers and musicians already familiar with using tape recorders to become familiar with the new systems. Therefore, computer-based DAWs tend to have a standard layout which includes transport controls (play, rewind, record, etc.), track controls and/or a mixer, and a waveform display. In single-track DAWs, only one (mono or stereo form) sound is displayed at a time. Multitrack DAWs support operations on multiple tracks at once. Like a mixing console, each track typically has controls that allow the user to adjust the overall volume and stereo balance (pan) of the sound on each track. In a traditional recording studio additional processing is physically plugged in to the audio signal path. However, a DAW can also route in software or use software plugins to process the sound on a track. DAWs are capable of many of the same functions as a traditional tape-based studio setup, and in recent years have almost completely replaced them. Modern advanced recording studios may have multiple types of DAWs in them and it is not uncommon for a sound engineer and/or musician to travel with a portable laptop-based DAW, although interoperability between different DAWs is poor. Perhaps the most significant feature available from a DAW that is not available in analogue recording is the ability to 'undo' a previous action. Undo makes it much easier to avoid accidentally permanently erasing or recording over a previous recording. If a mistake is made, the undo command is used to conveniently revert the changed data to a previous state. Cut, Copy, Paste, and Undo are familiar and common computer commands and usually available in DAWs in some form. Commonly DAWs feature some form of automation, often performed through "envelopes". Envelopes are procedural line segment-based or curve-based interactive graphs. The lines and curves of the automation graph are joined by or comprise adjustable points. By creating and adjusting multiple points along a waveform or control events, the user can specify parameters of the output over time (e.g., volume or pan). Automation data may also be directly derived from human gestures recorded by a control surface or controller. MIDI is a common data protocol used for transferring such gestures to the DAW. MIDI recording, editing, and playback is increasingly incorporated into modern DAWs of all types, as is Synchronization with other audio and/or video tools.
Free and open source software
There are many free and open-source software programs that can facilitate a DAW. These are often designed to run on a variety of operating systems and are usually developed non-commercially. The development of digital audio for Linux and BSD fostered technologies such as ALSA, which drives audio hardware, and JACK. JACK allows any JACK-aware audio software to connect to any other audio software running on the system, such as connecting an ALSA- or OSS-driven soundcard to a mixing and editing front-end, like Ardour or Rosegarden. In this way, JACK acts as a virtual audio patch bay, and it can be configured to use a computer's resources in real time, with dedicated memory, and with various options that minimize the DAW's latency. This kind of abstraction and configuration allows DJs to use multiple programs for editing and synthesizing audio streams, or multitasking and duplexing, without the need for analogue conversion, or asynchronous saving and reloading files, and ensures a high level of audio fidelity. Audacity is a free and open-source digital audio editor that can run on Mac OS X, Microsoft Windows, and Linux; it is particularly popular in the podcast community, and also has a large following among the visually impaired due to its keyboard interface. Macaw is a public domain source code music program that runs on Microsoft Windows. It features a large number of built in instrument synthesizers and effects, and it can load and play SoundFonts. Rosegarden is a multi-featured audio application that includes audio mixing plugins, a notation editor, and MIDI matrix editor. The MusE Sequencer is a similarly featured audio application that includes an audio mixer and a MIDI sequencer. Other open-source programs include virtual synthesizers and MIDI controllers, such as those provided by FluidSynth and TiMidity. Both can load SoundFonts to expand the voices and instruments available for synthesis and expand the ports and channels available to synthesizers. Such virtualization allows users to expand the traditional limitations of ADC-DAC hardware. The Linux Audio Development (LAD) mailing list is a major driving force in developing standards, such as the LADSPA, DSSI and LV2 plugin architectures. The Virtual Studio Technology (VST) plugin standard is supported as an option by some such programs but is generally implemented as a separate plugin, not a built-in option, due to Steinberg's licensing scheme. Among others, the creators of Audacity provide an optional, somewhat minimalist, VST-to-LADSPA bridge plugin for their software, but it is a separate download.