John Whitney Permutations (USA, 1971)
One of the most important aspects of John Whitney's production is the utilization of what he defined as "Computational Periodics". In other words, the achievement of a "series of harmonic events in the audiovisual presentation", where a specific simulation of a musical progression can be achieved through the multiple superimposition of graphic objects in order to create symmetries and counterpoints similar to the ones concerning rhythm and music. When John Whitney was called to the IBM laboratories as an artist-in-residence, thanks to the aid of Dr. Jack Citron he got in contact with a subroutine bookshop of FORTRAN language by the name of GRAF (Graphic Additions to FORTRAN), born with the purpose to support some of the IBM 360's characteristics. Through this bookshop, Citron and Whitney worked to the realization of Permutations, whose kinetic rhythms and phase relations created by the points movement produce perceptive effects strictly linked to tension modulation in music. According to Whitney himself: "In Permutations each point moves at a different speed and moves in a direction independent according to natural laws quite as valid as those of Pythagoras, while moving in their circular field. Their action produces a phenomenon more or less equivalent to the musical harmonies. When the points reach certain relationships (harmonic) numerical to other parameters of the equation, they form elementary figures.