In a broad sense, computer music is any music constructed, reproduced or performed with the aid of computer technology. More specifically, the term usually refers to real-time music a computer software program generates based on a predetermined set of constraints. Less commonly, the term can mean the study of the technologies used in music composition.
Real-time music generated by computers often relies on technologies such as synthesis and digital signal processing. These technologies, wrapped up in or connected to specific software programs, arrange sequences of individual sounds, note durations and pitches. The user of the program then executes a simple command such as clicking a "Play" button so the program can translate the sequence into sounds easily distributed through speakers. The hallmark of this type of music is that the computer essentially becomes the musician. This means the music is easy to transport and, very often, cheaper to produce than using live players or singers.
A major advantage of real-time computer music is that the associated programs are capable of producing sounds generally not possible through other sources. This often is done through mixing and layering different audio tracks. For instance, a musician could mix the sound of a lion roar with the sound of a car engine to produce a new, unique sound. He then could further adjust the pitch and incorporate the sound into the framework of the music. The fact real-time computer music has almost limitless combinations of sounds that can be generated means that people have a virtually unlimited compositional palette with which to work. Composition can extend beyond what "regular" musicians are technically capable of playing or singing.
Computer music does not always have to be heard. The best example of non-auditory computer music is sheet music produced through programs such as Sibelius® and Finale®. Users of these types of programs input information about pitches and their duration through QUERTY or music keyboards, which the computer programs translate into readable music symbols. Musicians then can save the entered data or print it out for performance with real players and singers. Sometimes non-auditory computer music links to auditory computer music, such as if the program is capable of playing back the entered pitches using midi or sampled-sound libraries.
The fact computers are a relatively new technology means that computer music is still developing. Compared to other genres of music, computer music is considered contemporary and even avante garde. This doesn't mean it is uncommon, however. For instance, many film composers incorporate computer music into their soundtracks when a project has a lower budget or when they feel the scene requires "unearthly" sounds to create just the right mood. Some universities also offer programs specifically designed for computer music.
People who study music made with computers are challenged by the fact new technologies develop regularly. Programs or techniques often have a very short lifespan. Additionally, the creativity required in music constantly drives musicians to think about how they might link different technologies to build new effects.