2. BRAZIL

3. VOX POPULI is WINNER of The International Competition Dream Centenary Computer Graphics in Aizu, Japan

5. In VOX POPULI… Individuals of the population are defined as groups of four voices. These voices are randomly generated on the interval [0…127], which corresponds to MIDI events: pitch is represented by the MIDI note table; duration depends on the rhythmic genetic cycle ; loudness is related to MIDI velocity table; timbre is given by the General MIDI instrument definition.

6. 1010111110011011001111110001

7. Rhythmic Genetic Cycle REPRODUCTION CROSSOVER MUTATION FITNESS 1010101101110100001011110101 1011111000110111011010000101 1010001011110111001110101101 1011111000110111011010000101 Current best chord interface

8. Voices Range Criterion

9. Consonance Criterion Co(N 1, N 2 ) =  Intersection(N 1, N 2 )

10. Musical Fitness Octave Fitness O =  Max(Oc(x i ))/4, i = 1, 4; Melodic Fitness M(N 1, N 2, N 3, N 4 ) = Max[C Id (N j )],j = 1, 4; where C Id (N j ) = Co(N j, Id). Harmonic Fitness Max(Co(N 1, N 2 ), Co(N 2, N 3, ), Co(N 3, N 4 ), Co(N 4, N 1 )

11. Musical Fitness F(O, M, H) = Octave Fitness + Melodic Fitness + Harmonic Fitness

12. Interface and Parameter Control Melodic Control Octave Control Biological Control Rhythmic Control Orchestra Control

13. Interactive Pad Control Red Curve Melodic Control Octave Control Blue Curve Biological Control Rhythmic Control

14. Fitness Displays Notes fitness, on the top; In the middle, a bar graph shows the four voices (bass, tenor, contralto, soprano) and their value The last shows the melodic, harmonic and octave fitness plot.

15. Sound Examples

16. We would like to thank our fellow student Leonardo N. S. Pereira for developing the routines to evaluate the consonance criterion. This work was supported by FAPESP (São Paulo State Research Foundation, process no. 95/08479-3), CTI (Technological Center for Informatics), and CNPq (process no. 300910/96-7).