Introduction: Interactive music also known as nonlinear music or adaptive music is synonymous with soundtracks to interactive media and in particular computer games. (En.wikipedia.org/wiki/Interactive_music )
Instruments (software/hardware):
Interactive music evolved out of electronic music, which evolved out of acoustic music, and the instruments used to compose and/or perform each kind of music suitably evolved too. The piano was the most popular and effective instrument for composing acoustic music, indeed electronic music started out using keyboard style instruments as synthesizers and the like. But interactive musicians are no longer bound to use one unifying instrument like the piano. Each particular composer can make their own instrument to suit their particular needs, so the musician is now "part performer, composer as well as hardware engineer" ( http://www.cim.mcgill.ca/~haptic/pub/BR-VH-IRCAM-00.pdf).
One exciting effective form of interactive music is using motion sensors to produce suitable expressive sounds, as seen in the work of Todd Winkler ( http://www.brown.edu/Departments/Music/sites/winkler). Software used in these practices include the NATO and BigEye video tracking systems, which can send certain information forward depending on where the gesture came from, its speed, and the size of the gesture. Software such as the Very Nervous System created by David Rokeby links video cameras, image processors, computers, synthesizers and a sound system to create a space in which the movements of one's body create sound and/or music ( http://homepage.mac.com/davidrokeby/vns.html).
In many ways these new instruments are not in fact instruments as they are not necessarily tangible produce the sound yourself instruments like a saxophone or a guitar, but they are no less expressive and I'm sure virtuosity could be achieved to produce new and exciting sounds.
Interactive Music – Composition:
The idea of composition in Interactive music means that the music is composed by interaction. In Interactive music, the interacting subjects are essentially the composers, as they decide the direction of the music. Whilst software and hardware, as mentioned above, has put numerous new sounds on the musician's desktop and can also be used to compose music, just like acoustic instruments and notation, several artificial-intelligence (AI) techniques have also been applied to algorithmic composition. Vox Populi uses a population of chords codified according to MIDI protocol and the application of genetic algorithms to manipulate/compose music via Graphical controls. (GA - http://en.wikipedia.org/wiki/Genetic_algorithm)
(http://www.mitpressjournals.org/doi/abs/10.1162/096112100570602?cookieSet=1&journalCode=lmj )
Similarly, using interactive genetic algorithms (GAs) and music theory music can be composed using Human Evaluation. One piece of music corresponds to one chromosome containing information on a melody. A user listens to the presented music and evaluates whether it fits his/her feeling, and essentially the system composes music reflecting his/her feelings of music. (http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=1008872 )
An American museum, Experience Music Project (EMP), provides an interaction based learning and compositional experience for its' visitors. Visitors to EMP will take an unprecedented and technologically advanced journey that will inspire them to explore and celebrate music, thus making them the composer of the musical sounds through interaction.
(EMP - http://www.emplive.org/aboutEMP/index.asp )
Music is also composed using interaction in theatre. Piano Bar: The Interactive Musical is a new musical by Stephen Cole and Matthew Ward, which draws on both the audience and the cast for its music composition. (http://www.nytheatre.com/nytheatre/pian4495.htm ) Music in theatre is not as restricted to a set score as it was in the history of theatre. The play may take its own momentum and the orchestra or musical elements play along, sometimes featuring improvisation.
Gaming:
A big part of the interactive music scene at this time is games. These games give the user a fun and easy look into the world of interactive music.Here is an example of a few web based interactive music games to get the feel for them http://www.audiogame.net/mainpage.html The main difference of interactive music in games is that compared to the music in for example a movie or T.V. the music suggests what is going to happen, not what has already happened. In other words the music will kick in after an event or change of mood has happened. This is what triggers the change in music for a game. In a movie the music will foresee a certain event. E.g. an enemy appearing. The music becomes more sinister before the event.
Methods of applying Interactive music into games. 1. Tracker.
Using a program such as ""FastTracker 2" http://www.fasttracker2.com/ you can store samples in memory. Then using a set of sound channels you can trigger these samples with different effects; pitches etc. depending on the game mood these samples can appear in different order. The music is not entirely different as the same samples will be played but it gives the feel of a real time change in music due to players' actions. Some negative aspects are that it doesn't sound as glossy as a cd track, it takes a lot of programming to record the music and apply it to a game. It has been used in games such as "Unreal" developed by www.epicgames.com
2. Audio Streaming.
In this practice the musician would compose all of the music using whatever instruments he/she needs. Then these are sampled into long sample-files. If the game condition changes and different music is required the music streams from the cd/harddisk, and is cross-faded into the old music. The restriction of this is that the music has to be written in the same key to avoid a conflict between the 2 pieces.
Interactive music games. In 1987 a video game called "Otocky" was developed in Japan by "SEDIC". This allowed the end user to use a ball as a weapon. When the player would shoot the game would play and quantize a note with the beat in the background. Different items could be collected to alter the pitch and tempo of the song. ( http://en.wikipedia.org/wiki/Otocky)
A more advanced and to date interactive music game would be Electroplankton for the Nintendo ds. This is an interactive music game which allows the user to create music by choosing the different settings and using a touch screen to move the plankton around, the game picks up on the direction of movement, the speed in which a line was drawn, etc. and changes the tempo, pitch and other aspects. ( http://en.wikipedia.org/wiki/Electroplankton) It allows the user to create music in a fun and interactive environment.
Conclusion:
So interactive music as with any new form of music evolved out of something else (electronic/techno)
In our project we have demonstrated:
How interactive music is composed (Composition - By Maeve Garvan),
Instruments (software/hardware - By Rory Brady) used in interactive music,
And applications of interactive music (gaming - By Liam Lynch).