~Proceedings ICMCISMCI2014 14-20 September 2014, Athens, Greece
ing keyboards as the input device, however, nowadays the
facto standard is the use of peripheral devices either similar in shape to the musical instruments (Guitar Hero, Rock
Band etc.) or real musical instruments (e.g. Rocksmith).
There are also some educational games in this genre which
are intended to teach beginners how to play musical instruments (e.g. Joytunes, 1).
Although at first glance similar, those games and our approach differs in several fundamental ways. In our work
games are created in a way that encourages creativity and
improvisation, while in rhythm games, players are supposed to mimic predefined actions as close as possible.
Another difference is that music rhythm games have themes
related to music playing, whereas our games are just generalthemed video games.
On the other hand video games have also influenced music. The most notable example is the creation of new music genres, two of which are: game soundtracks, and those
based on musical application of game consoles - chiptunes
. There were also more subtle influences. First of all,
the aforementioned use of generative music in games made
the idea of algorithmic composition known and accessible
for the general public. Second worth mentioning influence
is the usage of sound effects, characteristic synthesis techniques, and motifs from the game music to evoke certain
moods associated with the video games. Two interesting
systems such as scrabble2midi  and "Music for 32 Chess
Pieces"  use sonification of game states as the main musical element. In these systems the game controls the generation of music, our work also includes the opposite direction, where music controls the game.
More closely related to our work is the application of
game elements in musical composition and improvisation.
One of the earliest examples is the eighteenth century Musikalisches Wurfelspiele , in which dice were used for choosing music segments form a given set of possibilities. Another example are the game-theory-based Xenakis' compositions, i.e. Stratigie and Duel . The work most relevant to our system is the so called "game pieces" - which
consists of sets of rules used in group improvisations. The
compositions by John Zorn (e.g. Cobra, Hockey, Lacrosse,
Xu Feng) are the best known game pieces. Two other
examples of game pieces by Shiba Tetsu can be found in
3. CONTROL AND ANALYSIS STAGE
We chose to divide each game into two modules which
communicates via the MIDI protocol. Those modules are
control/analysis and game. In this section we will discuss
the control modules which were created in the Max/MSP
environment. We have also used Sonuus i2M audio to
MIDI converters for simplifying the controls modules in
case of pitch related analysis.
3.1 Goals and Problems
There were few goals and problems which we needed to
answer during the design and implementation of the control modules. The first of them, and one of the two most
important, was choosing a control scheme which allows
players to take intended action in games. The most important factor in this scheme, which affects the level of control
that players have, is calibration of the analysis parameters.
Without correct calibration, there were situations where
players were not able to take action or many false readings occurred. Finetuning the parameters after any change
in the audio systems, change of microphones, levels, instruments, etc, was crucial to achieve correct performance.
The second most important problem was allowing musical
freedom for players. Since one of the main elements of
this project was improvisation, we wanted to avoid situations similar to the ones in rhythm games, where a player
can only repeat a predefined sequence of actions.
In the games where players were rewarded for performing
certain actions, we identified the risk of encouraging only
high intensity playing rather than the desired artistic expression. Two solutions to this problem were investigated.
First we consciously designed the games so they did not
encourage high intensity playing all the time. Second, we
introduced artificial limits to the number of events in given
periods of time above which, new events were ignored.
3.2 Control Schemes
There are many possibilities for which musical elements
should be involved in the control of the games. This section presents and comments on a few of them.
" dynamics- The use of dynamics for playing gave
players a natural control of the effect of their actions in the game by playing louder or softer. A
good example of this was the Pong game, where
the speed and direction of the paddle movement was
controlled by the intensity difference between two
musicians playing. In games where the possible actions were just one-off discrete events (such as in
Mustetris) we implemented two possibilities: The
first one was to set a threshold above which every
loudness measurement produced an action. We found
this impractical and limiting from musical point of
view. The second option was to define a "counter
trick". The counter trick took each value of dynamics measurement added it to the counter. When the
counter reached a limit, the action was triggered and
the counter is zeroed. This resulted in a simple yet
effective way for controlling the games without limiting musical freedom excessively.
" density - A similar idea is to use density of playing as a controlling element. We measured it either
by counting NOTEON messages (for MIDI instru
ments) or analyzing transients (for acoustic instruments). We have found that using density gives similar results to dynamics, but limits the types of music
textures possible to use.
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